diff --git a/frontend/src/components/MaterialSidebar.tsx b/frontend/src/components/MaterialSidebar.tsx
index 95b96f6..6bfb7dd 100644
--- a/frontend/src/components/MaterialSidebar.tsx
+++ b/frontend/src/components/MaterialSidebar.tsx
@@ -8,13 +8,13 @@ import TagLink from '@/components/TagLink'
 import { fetchMaterialTagTree, parseMaterialFilter } from '@/lib/materials'
 import { materialsKeys } from '@/lib/queryKeys'
 import { cn } from '@/lib/utils'
+import { useUITranslation } from '@/lib/useUITranslation'
 
 import type { CSSProperties, Dispatch, FC, ReactNode, SetStateAction } from 'react'
 
 import type { MaterialFilter, MaterialSidebarTag, Tag } from '@/types'
 
 const FILTERS: MaterialFilter[] = ['missing', 'present', 'any']
-const FILTER_LABELS: Record<MaterialFilter, string> = { present: '有', missing: '無', any: '全' }
 
 
 const px = (value: string): number => {
@@ -96,24 +96,27 @@ const updateMaterialFilterQuery = (
 const MaterialFilterButtons: FC<{ materialFilter: MaterialFilter
 				  onChange:       (materialFilter: MaterialFilter) => void }> = (
     { materialFilter, onChange },
-) => (
-    <div className="flex flex-wrap gap-2 justify-end md:justify-start flex-center">
-      <label className="my-auto text-sm font-bold">素材：</label>
-      {FILTERS.map (value => (
-	  <button
-	      key={value}
-	      type="button"
-	      onClick={() => onChange (value)}
-	      className={cn (
-		  'rounded-full border px-3 py-1 text-sm',
-		  (materialFilter === value
-		   ? ['border-sky-500 bg-sky-50 text-sky-700 dark:border-sky-400',
-		      'dark:bg-sky-950 dark:text-sky-100']
-		   : ['border-neutral-300 bg-white text-neutral-700 dark:border-stone-700',
-		      'dark:bg-stone-900 dark:text-stone-200']))}>
-	    {FILTER_LABELS[value]}
-	  </button>))}
-    </div>)
+) => {
+  const { label } = useUITranslation ('materials')
+  return (
+      <div className="flex flex-wrap gap-2 justify-end md:justify-start flex-center">
+	<label className="my-auto text-sm font-bold">{label ('sidebar.label')}</label>
+	{FILTERS.map (value => (
+	    <button
+		key={value}
+		type="button"
+		onClick={() => onChange (value)}
+		className={cn (
+		    'rounded-full border px-3 py-1 text-sm',
+		    (materialFilter === value
+		     ? ['border-sky-500 bg-sky-50 text-sky-700 dark:border-sky-400',
+			'dark:bg-sky-950 dark:text-sky-100']
+		     : ['border-neutral-300 bg-white text-neutral-700 dark:border-stone-700',
+			'dark:bg-stone-900 dark:text-stone-200']))}>
+	      {label (`sidebar.${value}`)}
+	    </button>))}
+      </div>)
+}
 
 
 const MaterialTreeNode: FC<{
@@ -385,6 +388,7 @@ const MobileMaterialTreeNode: FC<{ depth?: number
 
 
 const MaterialSidebar: FC = () => {
+  const { label } = useUITranslation ('materials')
   const locale = useLocale ()
   const location = useLocation ()
   const navigate = useLocaleNavigate ()
@@ -498,10 +502,12 @@ const MaterialSidebar: FC = () => {
 		materialFilter={materialFilter}
 		onChange={handleFilterChange}/>
 	    {isLoading && (
-		<p className="text-sm text-neutral-500 dark:text-stone-400">読込中……</p>)}
+		<p className="text-sm text-neutral-500 dark:text-stone-400">
+		  {label ('shared:messages.loadingEllipsis')}
+		</p>)}
 	    {isError && (
 		<p className="text-sm text-red-600 dark:text-red-300">
-		  タグ一覧の取得に失敗しました．
+		  {label ('sidebar.error')}
 		</p>)}
 	    {(!isLoading && !isError) && (
 		<ul>
diff --git a/frontend/src/components/PostEditForm.tsx b/frontend/src/components/PostEditForm.tsx
index 3cd7cf2..7c84726 100644
--- a/frontend/src/components/PostEditForm.tsx
+++ b/frontend/src/components/PostEditForm.tsx
@@ -13,6 +13,7 @@ import useDialogue from '@/lib/dialogues/useDialogue'
 import { updatePost } from '@/lib/posts'
 import { msToTime } from '@/lib/utils'
 import { useValidationErrors } from '@/lib/useValidationErrors'
+import { useUITranslation } from '@/lib/useUITranslation'
 
 import type { FC, FormEvent } from 'react'
 
@@ -53,6 +54,7 @@ type Props = { post:    Post
 
 const PostEditForm: FC<Props> = ({ post, onSave }) => {
   const locale = useLocale ()
+  const { label } = useUITranslation ('posts')
   const [disabled, setDisabled] = useState (false)
   const [duration, setDuration] = useState<string> (videoMsToDurationValue (post.videoMs))
   const { baseErrors, fieldErrors, clearValidationErrors, applyValidationError } =
@@ -88,7 +90,7 @@ const PostEditForm: FC<Props> = ({ post, onSave }) => {
 		siblingPosts:           data.siblingPosts,
 		originalCreatedFrom:    data.originalCreatedFrom,
 		originalCreatedBefore:  data.originalCreatedBefore } as Post)
-      toast ({ description: '更新しました．' })
+      toast ({ description: label ('shared:messages.updated') })
     }
     catch (e)
     {
@@ -98,24 +100,28 @@ const PostEditForm: FC<Props> = ({ post, onSave }) => {
 	{
 	  if (applyValidationError (e))
 	    {
-	      toast ({ description: '更新はできなかったよ……' })
+	      toast ({ description: label ('edit.validationFailed') })
 	      return
 	    }
 
-	  toast ({ title: '失敗……', description: '入力を確認してください．' })
+	  toast ({ title: label ('shared:messages.failed'),
+	      description: label ('shared:messages.checkInput') })
 
 	  return
 	}
 
       const action = await dialogue.choice ({
-	  title: '競合が発生しました．',
+	  title: label ('edit.conflictTitle'),
 	  description: (
 	      <div>
-		<p>ほかの耕作員が先に更新してゐます．</p>
-		<p>現在の変更をどう扱ひますか?</p>
+		<p>{label ('edit.conflictDescription')}</p>
+		<p>{label ('edit.conflictQuestion')}</p>
 	      </div>),
-	  choices: [...(response?.data?.mergeable ? [{ value: 'merge', label: '差分をマージ' }] : []),
-		    { value: 'overwrite', label: '強制上書き', variant: 'danger' }] })
+	  cancelText: label ('shared:actions.cancel'),
+	  closeLabel: label ('settings:actions.close'),
+	  choices: [...(response?.data?.mergeable
+	      ? [{ value: 'merge', label: label ('edit.merge') }] : []),
+	      { value: 'overwrite', label: label ('edit.overwrite'), variant: 'danger' }] })
 
       if (action === 'merge')
 	{
@@ -165,13 +171,13 @@ const PostEditForm: FC<Props> = ({ post, onSave }) => {
 	<FieldError messages={baseErrors}/>
 
 	<PostTextField
-	    label="タイトル"
+	    label={label ('shared:labels.title')}
 	    value={title ?? ''}
 	    disabled={disabled}
 	    onChange={setTitle}/>
 
 	<PostTextField
-	    label="親投稿"
+	    label={label ('shared:labels.parentPosts')}
 	    value={parentPostIds}
 	    disabled={disabled}
 	    errors={fieldErrors.parentPostIds}
@@ -204,7 +210,7 @@ const PostEditForm: FC<Props> = ({ post, onSave }) => {
 
 	{/* 送信 */}
 	<Button type="submit" disabled={disabled}>
-	  更新
+	  {label ('shared:actions.update')}
 	</Button>
       </form>)
 }
diff --git a/frontend/src/components/common/TabGroup.tsx b/frontend/src/components/common/TabGroup.tsx
index 128e2dc..759fa12 100644
--- a/frontend/src/components/common/TabGroup.tsx
+++ b/frontend/src/components/common/TabGroup.tsx
@@ -3,7 +3,7 @@ import type { FC } from 'react'
 import React, { useState } from 'react'
 import { cn } from '@/lib/utils'
 
-type TabProps = { name:     string
+type TabProps = { name:     React.ReactNode
 		  init?:    boolean
 		  children: React.ReactNode }
 
diff --git a/frontend/src/components/dialogues/DialogueProvider.tsx b/frontend/src/components/dialogues/DialogueProvider.tsx
index bfe88e7..36c27c1 100644
--- a/frontend/src/components/dialogues/DialogueProvider.tsx
+++ b/frontend/src/components/dialogues/DialogueProvider.tsx
@@ -179,7 +179,8 @@ const DialogueProvider: FC<Props> = ({ children }) => {
 		    closeRequest (active.id, active.kind !== 'confirm' && null)
 		}}>
 	      <DialogContent
-		  closeLabel={active.kind === 'confirm' ? active.options.closeLabel : undefined}
+		  closeLabel={(active.kind === 'confirm' || active.kind === 'choice')
+		      ? active.options.closeLabel : undefined}
 		  className={
 		      active.kind === 'form'
 		      ? `flex max-h-[calc(100dvh-1rem)] ${ active.options.size === 'large'
diff --git a/frontend/src/lib/dialogues/useDialogue.ts b/frontend/src/lib/dialogues/useDialogue.ts
index d4ab77d..9ab65d7 100644
--- a/frontend/src/lib/dialogues/useDialogue.ts
+++ b/frontend/src/lib/dialogues/useDialogue.ts
@@ -16,13 +16,14 @@ type AlertOptions = { title:        string
 		      okText?:      string }
 
 type Choice<T extends string> = { value:    T
-				  label:    string
+				  label:    ReactNode
 				  variant?: DialogueVariant }
 
-type ChoiceOptions<T extends string> = { title:         string
+type ChoiceOptions<T extends string> = { title:         ReactNode
 					 description?:  ReactNode
 					 choices:       Choice<T>[]
-					 cancelText?:   string }
+					 cancelText?:   ReactNode
+					 closeLabel?:   ReactNode }
 
 type DialogueFormAction = {
   label:      string
diff --git a/frontend/src/locales/ain-Kana/common.json b/frontend/src/locales/ain-Kana/common.json
index 8fdb166..eb291b1 100644
--- a/frontend/src/locales/ain-Kana/common.json
+++ b/frontend/src/locales/ain-Kana/common.json
@@ -2,8 +2,8 @@
   "categoryLabel": "イソネカ",
   "stateLabel": "シㇼキ",
   "search": "イフナラ",
-  "loading": "タツ゚ㇺ　アウㇰ　コㇿ　アン…",
-  "fetchError": "タツ゚ㇺ　アウㇰ　エアイカㇷ゚",
+  "loading": "タトゥㇺ　アウㇰ　コㇿ　アン…",
+  "fetchError": "タトゥㇺ　アウㇰ　エアイカㇷ゚",
   "states": { "active": "アㇱカイ",
 	      "deprecated": "タネ　ソモ　アエイワンケ" },
   "categories": { "deerjikist": "ユㇰ　ニチカ　ウタㇻ",
diff --git a/frontend/src/locales/ain-Kana/materials.json b/frontend/src/locales/ain-Kana/materials.json
new file mode 100644
index 0000000..bf1e1e1
--- /dev/null
+++ b/frontend/src/locales/ain-Kana/materials.json
@@ -0,0 +1,20 @@
+{
+  "title": "素材管理",
+  "newTitle": "素材追加",
+  "detailTitle": "{{name}} 素材照会",
+  "unnamed": "素材 #{{id}}",
+  "media": { "image": "画像", "video": "動画", "audio": "音声", "file_other": "その他ファイル", "url_only": "URL のみ" },
+  "mediaFilter": { "all": "$t(navigation:list)", "image": "$t(materials:media.image)", "video": "$t(materials:media.video)", "audio": "$t(materials:media.audio)", "file_other": "$t(materials:media.file_other)", "url_only": "外部リンクのみ" },
+  "sort": { "created_at": "作成日時", "updated_at": "$t(tags:updatedAt)", "tag_name": "$t(history:tagName)", "media_kind": "種類", "file_byte_size": "容量", "version_no": "$t(history:version)", "id": "Id." },
+  "kindPrefix": "種類: ", "sizePrefix": "サイズ: ", "urlPrefix": "URL: ", "createdPrefix": "作成: ",
+  "other": "その他", "descendantScope": " 配下の素材を表示中", "tagScope": " の素材を表示中", "clearTag": "タグ選択を解除", "tagMissing": "選択中タグが見つかりません．", "searchTop": "素材検索トップへ戻る", "searchPlaceholder": "タグ名 / URL / ファイル名", "tagState": "タグ状態", "tagged": "タグあり", "mediaLabel": "メディア", "cardView": "アイコン", "listView": "詳細", "descending": "降順", "ascending": "昇順", "listError": "素材一覧の取得に失敗しました．", "empty": "素材はありません。", "pleaseAdd": "追加してください",
+  "file": "ファイル", "referenceUrl": "参考 URL", "exportPath": "ZIP 出力パス", "exportPlaceholder": "伊地知ニジカ/表情/泣き.png", "preview": "preview", "unsupportedFile": "その形式のファイルには対応していません．", "sent": "送信成功!", "sendFailed": "送信失敗……", "updated": "更新成功!", "updateFailed": "更新失敗……", "detailError": "素材の取得に失敗しました．", "missing": "素材が見つかりませんでした．",
+  "sidebar": { "label": "素材：", "present": "有", "missing": "無", "any": "全", "error": "タグ一覧の取得に失敗しました．" },
+  "suppressions": {
+    "title": "素材同期抑止", "heading": "$t(navigation:suppressions)",
+    "sourceKind": "同期元種別", "sourceUri": "同期元 URI", "drivePath": "Google Drive パス", "driveFileId": "Google Drive ファイル Id.", "reason": "事由", "register": "登録", "reasonPrefix": "事由: ", "registeredPrefix": "登録: ", "registered": "同期元抑止を登録しました", "registerFailed": "同期元抑止の登録に失敗しました", "error": "同期元抑止一覧の取得に失敗しました．",
+    "sources": { "uri": "URI", "google_drive_path": "Google Drive ファイル", "google_drive_path_prefix": "Google Drive フォルダ", "google_drive_file": "Google Drive ファイル Id.", "legacy_drive_path": "汎用ファイル", "legacy_drive_path_prefix": "汎用フォルダ" },
+    "reasons": { "copyright_high_risk": "著作権への懸念", "copyright_takedown": "著作者からの申出", "adult_or_sensitive": "成人向け", "personal_information": "個人情報", "malware_or_dangerous_file": "危険なソフトウェア", "duplicate_or_low_quality": "重複", "source_owner_request": "同期元管理者からの申出", "other": "その他" }
+  },
+  "_untranslated": ["title", "newTitle", "detailTitle", "unnamed", "media", "mediaFilter.url_only", "sort.created_at", "sort.media_kind", "sort.file_byte_size", "kindPrefix", "sizePrefix", "createdPrefix", "other", "descendantScope", "tagScope", "clearTag", "tagMissing", "searchTop", "searchPlaceholder", "tagState", "tagged", "mediaLabel", "cardView", "listView", "descending", "ascending", "listError", "empty", "pleaseAdd", "file", "referenceUrl", "exportPath", "exportPlaceholder", "preview", "unsupportedFile", "sent", "sendFailed", "updated", "updateFailed", "detailError", "missing", "sidebar", "suppressions.title", "suppressions.sourceKind", "suppressions.sourceUri", "suppressions.drivePath", "suppressions.driveFileId", "suppressions.reason", "suppressions.register", "suppressions.reasonPrefix", "suppressions.registeredPrefix", "suppressions.registered", "suppressions.registerFailed", "suppressions.error", "suppressions.sources.google_drive_path", "suppressions.sources.google_drive_path_prefix", "suppressions.sources.google_drive_file", "suppressions.sources.legacy_drive_path", "suppressions.sources.legacy_drive_path_prefix", "suppressions.reasons"]
+}
diff --git a/frontend/src/locales/ain-Kana/posts.json b/frontend/src/locales/ain-Kana/posts.json
new file mode 100644
index 0000000..8d19d02
--- /dev/null
+++ b/frontend/src/locales/ain-Kana/posts.json
@@ -0,0 +1,11 @@
+{
+  "edit": {
+    "validationFailed": "更新はできなかったよ……",
+    "conflictTitle": "競合が発生しました．",
+    "conflictDescription": "ほかの耕作員が先に更新してゐます．",
+    "conflictQuestion": "現在の変更をどう扱ひますか?",
+    "merge": "差分をマージ",
+    "overwrite": "強制上書き"
+  },
+  "_untranslated": ["edit"]
+}
diff --git a/frontend/src/locales/ain-Kana/theatres.json b/frontend/src/locales/ain-Kana/theatres.json
new file mode 100644
index 0000000..422d00f
--- /dev/null
+++ b/frontend/src/locales/ain-Kana/theatres.json
@@ -0,0 +1,8 @@
+{
+  "title": "上映会場", "namedTitle": "上映会場『{{name}}』",
+  "layouts": { "threeColumns": "3 列", "tagsBottom": "2 列 A 型", "commentsBottom": "2 列 B 型" },
+  "flows": { "vertical": "縦並び", "horizontal": "横並び" },
+  "staff": "運営", "deleted": "削除されました．", "authorPrefix": "by ", "commentSuffix": " へのコメント",
+  "comments": "コメント", "commentPlaceholder": "ここにコメントを入力", "deleteComment": "コメントを削除", "confirmDelete": "このコメントを削除しますか?", "delete": "削除", "noTags": "タグはありません。", "participants": "参加者", "history": "再生履歴", "emptyHistory": "まだ履歴はありません。", "weights": "抽選重み", "unlikelyTags": "出にくいタグ", "emptyPenalties": "まだ減点はありません。", "unlikelyPosts": "出にくい候補", "likelyPosts": "出やすい候補", "watching": "同接 {{count}} 人", "cancelSkip": "スキップ取消", "selecting": "次の投稿を選んでゐます……", "waiting": "上映待機中", "playing": "再生中", "unselected": "未選択", "close": "閉じる", "editingPost": "編輯中の投稿", "editingSuffix": "を編輯中……", "emptyPosts": "候補はありません。", "penalty": "penalty {{value}}", "weight": "weight {{value}}",
+  "_untranslated": ["title", "namedTitle", "layouts", "flows", "staff", "deleted", "authorPrefix", "commentSuffix", "comments", "commentPlaceholder", "deleteComment", "confirmDelete", "delete", "noTags", "participants", "history", "emptyHistory", "weights", "unlikelyTags", "emptyPenalties", "unlikelyPosts", "likelyPosts", "watching", "cancelSkip", "selecting", "waiting", "playing", "unselected", "close", "editingPost", "editingSuffix", "emptyPosts", "penalty", "weight"]
+}
diff --git a/frontend/src/locales/ja/materials.json b/frontend/src/locales/ja/materials.json
new file mode 100644
index 0000000..d0064cd
--- /dev/null
+++ b/frontend/src/locales/ja/materials.json
@@ -0,0 +1,51 @@
+{
+  "title": "素材管理",
+  "newTitle": "素材追加",
+  "detailTitle": "{{name}} 素材照会",
+  "unnamed": "素材 #{{id}}",
+  "media": { "image": "画像", "video": "動画", "audio": "音声", "file_other": "その他ファイル", "url_only": "URL のみ" },
+  "mediaFilter": { "all": "すべて", "image": "$t(materials:media.image)", "video": "$t(materials:media.video)", "audio": "$t(materials:media.audio)", "file_other": "$t(materials:media.file_other)", "url_only": "外部リンクのみ" },
+  "sort": { "created_at": "作成日時", "updated_at": "更新日時", "tag_name": "タグ名", "media_kind": "種類", "file_byte_size": "容量", "version_no": "版", "id": "Id." },
+  "kindPrefix": "種類: ",
+  "sizePrefix": "サイズ: ",
+  "urlPrefix": "URL: ",
+  "createdPrefix": "作成: ",
+  "other": "その他",
+  "descendantScope": " 配下の素材を表示中",
+  "tagScope": " の素材を表示中",
+  "clearTag": "タグ選択を解除",
+  "tagMissing": "選択中タグが見つかりません．",
+  "searchTop": "素材検索トップへ戻る",
+  "searchPlaceholder": "タグ名 / URL / ファイル名",
+  "tagState": "タグ状態",
+  "tagged": "タグあり",
+  "mediaLabel": "メディア",
+  "cardView": "アイコン",
+  "listView": "詳細",
+  "descending": "降順",
+  "ascending": "昇順",
+  "listError": "素材一覧の取得に失敗しました．",
+  "empty": "素材はありません。",
+  "pleaseAdd": "追加してください",
+  "file": "ファイル",
+  "referenceUrl": "参考 URL",
+  "exportPath": "ZIP 出力パス",
+  "exportPlaceholder": "伊地知ニジカ/表情/泣き.png",
+  "preview": "preview",
+  "unsupportedFile": "その形式のファイルには対応していません．",
+  "sent": "送信成功!",
+  "sendFailed": "送信失敗……",
+  "updated": "更新成功!",
+  "updateFailed": "更新失敗……",
+  "detailError": "素材の取得に失敗しました．",
+  "missing": "素材が見つかりませんでした．",
+  "sidebar": { "label": "素材：", "present": "有", "missing": "無", "any": "全", "error": "タグ一覧の取得に失敗しました．" },
+  "suppressions": {
+    "title": "素材同期抑止", "heading": "同期抑止",
+    "sourceKind": "同期元種別", "sourceUri": "同期元 URI", "drivePath": "Google Drive パス", "driveFileId": "Google Drive ファイル Id.",
+    "reason": "事由", "register": "登録", "reasonPrefix": "事由: ", "registeredPrefix": "登録: ",
+    "registered": "同期元抑止を登録しました", "registerFailed": "同期元抑止の登録に失敗しました", "error": "同期元抑止一覧の取得に失敗しました．",
+    "sources": { "uri": "URI", "google_drive_path": "Google Drive ファイル", "google_drive_path_prefix": "Google Drive フォルダ", "google_drive_file": "Google Drive ファイル Id.", "legacy_drive_path": "汎用ファイル", "legacy_drive_path_prefix": "汎用フォルダ" },
+    "reasons": { "copyright_high_risk": "著作権への懸念", "copyright_takedown": "著作者からの申出", "adult_or_sensitive": "成人向け", "personal_information": "個人情報", "malware_or_dangerous_file": "危険なソフトウェア", "duplicate_or_low_quality": "重複", "source_owner_request": "同期元管理者からの申出", "other": "その他" }
+  }
+}
diff --git a/frontend/src/locales/ja/posts.json b/frontend/src/locales/ja/posts.json
new file mode 100644
index 0000000..d0c06aa
--- /dev/null
+++ b/frontend/src/locales/ja/posts.json
@@ -0,0 +1,10 @@
+{
+  "edit": {
+    "validationFailed": "更新はできなかったよ……",
+    "conflictTitle": "競合が発生しました．",
+    "conflictDescription": "ほかの耕作員が先に更新してゐます．",
+    "conflictQuestion": "現在の変更をどう扱ひますか?",
+    "merge": "差分をマージ",
+    "overwrite": "強制上書き"
+  }
+}
diff --git a/frontend/src/locales/ja/theatres.json b/frontend/src/locales/ja/theatres.json
new file mode 100644
index 0000000..5d01039
--- /dev/null
+++ b/frontend/src/locales/ja/theatres.json
@@ -0,0 +1,7 @@
+{
+  "title": "上映会場", "namedTitle": "上映会場『{{name}}』",
+  "layouts": { "threeColumns": "3 列", "tagsBottom": "2 列 A 型", "commentsBottom": "2 列 B 型" },
+  "flows": { "vertical": "縦並び", "horizontal": "横並び" },
+  "staff": "運営", "deleted": "削除されました．", "authorPrefix": "by ", "commentSuffix": " へのコメント",
+  "comments": "コメント", "commentPlaceholder": "ここにコメントを入力", "deleteComment": "コメントを削除", "confirmDelete": "このコメントを削除しますか?", "delete": "削除", "noTags": "タグはありません。", "participants": "参加者", "history": "再生履歴", "emptyHistory": "まだ履歴はありません。", "weights": "抽選重み", "unlikelyTags": "出にくいタグ", "emptyPenalties": "まだ減点はありません。", "unlikelyPosts": "出にくい候補", "likelyPosts": "出やすい候補", "watching": "同接 {{count}} 人", "cancelSkip": "スキップ取消", "selecting": "次の投稿を選んでゐます……", "waiting": "上映待機中", "playing": "再生中", "unselected": "未選択", "close": "閉じる", "editingPost": "編輯中の投稿", "editingSuffix": "を編輯中……", "emptyPosts": "候補はありません。", "penalty": "penalty {{value}}", "weight": "weight {{value}}"
+}
diff --git a/frontend/src/pages/materials/MaterialDetailPage.tsx b/frontend/src/pages/materials/MaterialDetailPage.tsx
index fba4219..24b26da 100644
--- a/frontend/src/pages/materials/MaterialDetailPage.tsx
+++ b/frontend/src/pages/materials/MaterialDetailPage.tsx
@@ -22,6 +22,7 @@ import {
 import { materialsKeys } from '@/lib/queryKeys'
 import { inputClass } from '@/lib/utils'
 import { useValidationErrors } from '@/lib/useValidationErrors'
+import { useUITranslation } from '@/lib/useUITranslation'
 
 import type { FC } from 'react'
 
@@ -30,6 +31,7 @@ type MaterialFormField = 'tag' | 'file' | 'url' | 'exportPaths'
 
 const MaterialDetailPage: FC = () => {
   const locale = useLocale ()
+  const { message, label } = useUITranslation ('materials')
   const { id } = useParams ()
   const qc = useQueryClient ()
 
@@ -46,7 +48,7 @@ const MaterialDetailPage: FC = () => {
       queryFn:  () => fetchMaterial (id ?? '', locale),
       enabled:  id != null})
   const materialTitle = material
-      ? material.tag?.name ?? `素材 #${ material.id }`
+      ? material.tag?.name ?? message ('unnamed', { id: material.id }).text
       : ''
 
   useEffect (() => {
@@ -83,11 +85,11 @@ const MaterialDetailPage: FC = () => {
       onSuccess: async data => {
 	qc.setQueryData (materialsKeys.show (id ?? '', locale), data)
 	await invalidateMaterialQueries ()
-	toast ({ title: '更新成功!' })
+	toast ({ title: label ('updated') })
       },
       onError: error => {
 	applyValidationError (error)
-	toast ({ title: '更新失敗……', description: '入力を見直してください．' })
+	toast ({ title: label ('updateFailed'), description: label ('shared:messages.reviewInput') })
       }})
 
   const handleSubmit = () => {
@@ -99,15 +101,15 @@ const MaterialDetailPage: FC = () => {
       <MainArea>
 	{material && (
 	    <Helmet>
-	      <title>{`${ materialTitle } 素材照会 | ${ SITE_TITLE }`}</title>
+	      <title>{message ('detailTitle', { name: materialTitle }).text} | {SITE_TITLE}</title>
 	    </Helmet>)}
 
-	{isLoading ? 'Loading...' : isError ? (
+	{isLoading ? label ('common:loading') : isError ? (
 	    <p className="text-red-600 dark:text-red-300">
-	      素材の取得に失敗しました．
+	      {label ('detailError')}
 	    </p>) : material == null ? (
 	    <p className="text-stone-700 dark:text-stone-300">
-	      素材が見つかりませんでした．
+	      {label ('missing')}
 	    </p>) : (
 	    <>
 	      <PageTitle>
@@ -117,7 +119,7 @@ const MaterialDetailPage: FC = () => {
 			tag={material.tag}
 			withWiki={false}
 			withCount={false}/>)
-		 : materialTitle}
+		 : label ('unnamed', { id: material.id })}
 	      </PageTitle>
 
 	      {(material.file && material.contentType) && (
@@ -136,11 +138,11 @@ const MaterialDetailPage: FC = () => {
 			  body={material.wikiPageBody ?? undefined}/>
 		    </Tab>)}
 
-		<Tab name="編輯">
+		<Tab name={label ('shared:actions.edit')}>
 		  <div className="max-w-wl space-y-4 pt-2">
 		    <FieldError messages={baseErrors}/>
 
-		    <FormField label="タグ" messages={fieldErrors.tag}>
+		    <FormField label={label ('navigation:tags')} messages={fieldErrors.tag}>
 		      {({ describedBy, invalid }) => (
 			  <TagInput
 			      describedBy={describedBy}
@@ -149,7 +151,7 @@ const MaterialDetailPage: FC = () => {
 			      setValue={setTag}/>)}
 		    </FormField>
 
-		    <FormField label="ファイル" messages={fieldErrors.file}>
+		    <FormField label={label ('file')} messages={fieldErrors.file}>
 		      {({ describedBy, invalid }) => (
 			  <>
 			    <input
@@ -167,7 +169,8 @@ const MaterialDetailPage: FC = () => {
 				(/image\/.*/.test (file.type) && (
 				    <img
 					src={filePreview}
-					alt="preview"
+					alt={message ('preview').text}
+					lang={message ('preview').language}
 					className="mt-2 max-h-48 rounded border"/>))
 				|| (/video\/.*/.test (file.type) && (
 				    <video
@@ -181,12 +184,12 @@ const MaterialDetailPage: FC = () => {
 					className="mt-2 max-h-48"/>))
 				|| (
 				    <p className="text-red-600 dark:text-red-400">
-				      その形式のファイルには対応していません．
+				      {label ('unsupportedFile')}
 				    </p>))}
 			  </>)}
 		    </FormField>
 
-		    <FormField label="参考 URL" messages={fieldErrors.url}>
+		    <FormField label={label ('referenceUrl')} messages={fieldErrors.url}>
 		      {({ describedBy, invalid }) => (
 			  <input
 			      type="url"
@@ -197,13 +200,14 @@ const MaterialDetailPage: FC = () => {
 			      className={inputClass (invalid)}/>)}
 		    </FormField>
 
-		    <FormField label="ZIP 出力パス" messages={fieldErrors.exportPaths}>
+		    <FormField label={label ('exportPath')} messages={fieldErrors.exportPaths}>
 		      {({ describedBy, invalid }) => (
 			  <input
 			      type="text"
 			      value={exportPath}
 			      onChange={e => setExportPath (e.target.value)}
-			      placeholder="伊地知ニジカ/表情/泣き.png"
+			      placeholder={message ('exportPlaceholder').text}
+			      lang={message ('exportPlaceholder').language}
 			      aria-describedby={describedBy}
 			      aria-invalid={invalid}
 			      className={inputClass (invalid)}/>)}
@@ -215,7 +219,7 @@ const MaterialDetailPage: FC = () => {
 			  className="rounded bg-blue-600 px-4 py-2 text-white
 				     disabled:bg-gray-400"
 			  disabled={updateMutation.isPending}>
-			更新
+			{label ('shared:actions.update')}
 		      </Button>
 		    </div>
 		  </div>
diff --git a/frontend/src/pages/materials/MaterialListPage.tsx b/frontend/src/pages/materials/MaterialListPage.tsx
index a8634aa..63c3f68 100644
--- a/frontend/src/pages/materials/MaterialListPage.tsx
+++ b/frontend/src/pages/materials/MaterialListPage.tsx
@@ -6,6 +6,7 @@ import { useLocation } from 'react-router-dom'
 import { useLocale, useLocaleNavigate } from '@/lib/useLocale'
 import nikumaru from '@/assets/fonts/nikumaru.otf'
 import PrefetchLink from '@/components/PrefetchLink'
+import LocalisedText from '@/components/LocalisedText'
 import DateTimeField from '@/components/common/DateTimeField'
 import FormField from '@/components/common/FormField'
 import PageTitle from '@/components/common/PageTitle'
@@ -14,7 +15,8 @@ import MainArea from '@/components/layout/MainArea'
 import { SITE_TITLE } from '@/config'
 import { fetchMaterials, parseMaterialFilter } from '@/lib/materials'
 import { materialsKeys } from '@/lib/queryKeys'
-import { cn, dateString, inputClass } from '@/lib/utils'
+import { cn, localisedDateString, inputClass } from '@/lib/utils'
+import { useUITranslation } from '@/lib/useUITranslation'
 
 import type { FC, FormEvent } from 'react'
 
@@ -30,28 +32,28 @@ import type { FetchMaterialsParams,
 	      MaterialIndexView } from '@/types'
 
 const MEDIA_KIND_LABELS: Record<Material['mediaKind'], string> = {
-    image:      '画像',
-    video:      '動画',
-    audio:      '音声',
-    file_other: 'その他ファイル',
-    url_only:   'URL のみ'}
+    image: 'media.image',
+    video: 'media.video',
+    audio: 'media.audio',
+    file_other: 'media.file_other',
+    url_only: 'media.url_only' }
 
 const MEDIA_FILTER_LABELS: Record<MaterialIndexMediaKind, string> = {
-    all:        'すべて',
-    image:      '画像',
-    video:      '動画',
-    audio:      '音声',
-    file_other: 'その他ファイル',
-    url_only:   '外部リンクのみ'}
+    all: 'mediaFilter.all',
+    image: 'mediaFilter.image',
+    video: 'mediaFilter.video',
+    audio: 'mediaFilter.audio',
+    file_other: 'mediaFilter.file_other',
+    url_only: 'mediaFilter.url_only' }
 
 const SORT_LABELS: Record<MaterialIndexSort, string> = {
-    created_at:     '作成日時',
-    updated_at:     '更新日時',
-    tag_name:       'タグ名',
-    media_kind:     '種類',
-    file_byte_size: '容量',
-    version_no:     '版',
-    id:             'Id.'}
+    created_at: 'sort.created_at',
+    updated_at: 'sort.updated_at',
+    tag_name: 'sort.tag_name',
+    media_kind: 'sort.media_kind',
+    file_byte_size: 'sort.file_byte_size',
+    version_no: 'sort.version_no',
+    id: 'sort.id' }
 
 
 const setIf = (qs: URLSearchParams, key: string, value: string | null) => {
@@ -78,10 +80,6 @@ const fileSizeText = (bytes: number | null): string => {
 }
 
 
-const materialTitle = (material: Material): string =>
-    material.tag?.name ?? `素材 #${ material.id }`
-
-
 const groupedTagPath = (
     tagId: number,
     materialFilter: MaterialFilter,
@@ -132,86 +130,104 @@ const MaterialThumb: FC<{ material: Material }> = ({ material }) => (
     </div>)
 
 
-const MaterialCard: FC<{ material: Material }> = ({ material }) => (
-    <article className="w-[180px] justify-self-center">
-      <PrefetchLink to={`/materials/${ material.id }`} className="block">
-	<MaterialThumb material={material}/>
-	<div className="mt-2 w-[180px]">
-	  <p className="truncate text-sm font-medium text-stone-900 dark:text-stone-100">
-	    {materialTitle (material)}
-	  </p>
-	  <p className="truncate text-xs text-stone-600 dark:text-stone-300">
-	    {MEDIA_KIND_LABELS[material.mediaKind]} / {dateString (material.createdAt)}
-	  </p>
-	</div>
-      </PrefetchLink>
-    </article>)
-
-
-const MaterialListItem: FC<{ material: Material }> = ({ material }) => (
-    <article
-	className="rounded-lg border border-stone-200 bg-white p-3 text-stone-900
-		   shadow-sm dark:border-stone-700 dark:bg-stone-900 dark:text-stone-100">
-      <div className="flex gap-3">
-	<MaterialThumb material={material}/>
-	<div className="min-w-0 flex-1 space-y-2">
-	  <div>
-	    <PrefetchLink
-		to={`/materials/${ material.id }`}
-		className="font-medium text-sky-700 underline underline-offset-2
-			   dark:text-sky-300">
-	      {materialTitle (material)}
-	    </PrefetchLink>
+const MaterialCard: FC<{ material: Material }> = ({ material }) => {
+  const locale = useLocale ()
+  const { label } = useUITranslation ('materials')
+  return (
+      <article className="w-[180px] justify-self-center">
+	<PrefetchLink to={`/materials/${ material.id }`} className="block">
+	  <MaterialThumb material={material}/>
+	  <div className="mt-2 w-[180px]">
+	    <p className="truncate text-sm font-medium text-stone-900 dark:text-stone-100">
+	      {material.tag?.name ?? label ('unnamed', { id: material.id })}
+	    </p>
+	    <p className="text-xs text-stone-600 dark:text-stone-300">
+	      {label (MEDIA_KIND_LABELS[material.mediaKind])} /{' '}
+	      <LocalisedText language={locale}>
+		{localisedDateString (material.createdAt, locale)}
+	      </LocalisedText>
+	    </p>
 	  </div>
-	  <dl className="space-y-1 text-sm text-stone-600 dark:text-stone-300">
+	</PrefetchLink>
+      </article>)
+}
+
+
+const MaterialListItem: FC<{ material: Material }> = ({ material }) => {
+  const locale = useLocale ()
+  const { label } = useUITranslation ('materials')
+  return (
+      <article
+	  className="rounded-lg border border-stone-200 bg-white p-3 text-stone-900
+		     shadow-sm dark:border-stone-700 dark:bg-stone-900 dark:text-stone-100">
+	<div className="flex flex-wrap gap-3">
+	  <MaterialThumb material={material}/>
+	  <div className="min-w-0 flex-1 space-y-2">
 	    <div>
-	      <dt className="inline">種類: </dt>
-	      <dd className="inline">{MEDIA_KIND_LABELS[material.mediaKind]}</dd>
+	      <PrefetchLink
+		  to={`/materials/${ material.id }`}
+		  className="font-medium text-sky-700 underline underline-offset-2
+			     dark:text-sky-300">
+		{material.tag?.name ?? label ('unnamed', { id: material.id })}
+	      </PrefetchLink>
 	    </div>
-	    {material.fileByteSize != null && (
-		<div>
-		  <dt className="inline">サイズ: </dt>
-		  <dd className="inline">{fileSizeText (material.fileByteSize)}</dd>
-		</div>)}
-	    {material.url && (
-		<div>
-		  <dt className="inline">URL: </dt>
-		  <dd className="inline break-all">{material.url}</dd>
-		</div>)}
-	    <div>
-	      <dt className="inline">作成: </dt>
-	      <dd className="inline">{dateString (material.createdAt)}</dd>
-	    </div>
-	  </dl>
+	    <dl className="space-y-1 text-sm text-stone-600 dark:text-stone-300">
+	      <div>
+		<dt className="inline">{label ('kindPrefix')}</dt>
+		<dd className="inline">{label (MEDIA_KIND_LABELS[material.mediaKind])}</dd>
+	      </div>
+	      {material.fileByteSize != null && (
+		  <div>
+		    <dt className="inline">{label ('sizePrefix')}</dt>
+		    <dd className="inline">{fileSizeText (material.fileByteSize)}</dd>
+		  </div>)}
+	      {material.url && (
+		  <div>
+		    <dt className="inline">{label ('urlPrefix')}</dt>
+		    <dd className="inline break-all">{material.url}</dd>
+		  </div>)}
+	      <div>
+		<dt className="inline">{label ('createdPrefix')}</dt>
+		<dd className="inline">
+		  <LocalisedText language={locale}>
+		    {localisedDateString (material.createdAt, locale)}
+		  </LocalisedText>
+		</dd>
+	      </div>
+	    </dl>
+	  </div>
 	</div>
-      </div>
-    </article>)
+      </article>)
+}
 
 
 const GroupHeading: FC<{
     count:          number
     materialFilter: MaterialFilter
     title:          string
-    tagId:          number
-}> = ({ count, materialFilter, title, tagId }) => (
-    <div className="flex items-center gap-2 border-b border-stone-200 pb-2
-		    dark:border-stone-700">
-      <PrefetchLink
-	  to={groupedTagPath (tagId, materialFilter)}
-	  className="font-medium text-sky-700 underline underline-offset-2
-		     dark:text-sky-300 w-full">
-	{title}
-      </PrefetchLink>
-      <div className="text-right w-auto">
-	<span className="text-nowrap text-sm text-stone-600 dark:text-stone-300">
-	  {count} 件
-	</span>
-      </div>
-    </div>)
+    tagId:          number }> = ({ count, materialFilter, title, tagId }) => {
+  const { label } = useUITranslation ('materials')
+  return (
+      <div className="flex flex-wrap items-center gap-2 border-b border-stone-200 pb-2
+		      dark:border-stone-700">
+	<PrefetchLink
+	    to={groupedTagPath (tagId, materialFilter)}
+	    className="min-w-0 flex-1 font-medium text-sky-700 underline underline-offset-2
+		       dark:text-sky-300">
+	  {title}
+	</PrefetchLink>
+	<div className="text-right w-auto">
+	  <span className="text-sm text-stone-600 dark:text-stone-300">
+	    {label ('shared:labels.resultsCount', { count })}
+	  </span>
+	</div>
+      </div>)
+}
 
 
 const MaterialListPage: FC = () => {
   const locale = useLocale ()
+  const { message, label } = useUITranslation ('materials')
   const location = useLocation ()
   const navigate = useLocaleNavigate ()
   const query = useMemo (() => new URLSearchParams (location.search), [location.search])
@@ -387,7 +403,7 @@ const MaterialListPage: FC = () => {
 	    <section className="space-y-3">
 	      <div className="border-b border-stone-200 pb-2 dark:border-stone-700">
 		<span className="font-medium text-stone-900 dark:text-stone-100">
-		  その他
+		  {label ('other')}
 		</span>
 	      </div>
 	      {renderMaterialCollection (ungroupedMaterials)}
@@ -405,12 +421,12 @@ const MaterialListPage: FC = () => {
 		  src: url(${ nikumaru }) format('opentype');
 		}`}
 	  </style>
-	  <title>{`素材管理 | ${ SITE_TITLE }`}</title>
+	  <title>{message ('title').text} | {SITE_TITLE}</title>
 	</Helmet>
 
 	<div className="space-y-5">
 	  <div className="flex flex-wrap items-center justify-between gap-3">
-	    <PageTitle className="my-auto">素材管理</PageTitle>
+	    <PageTitle className="my-auto">{label ('title')}</PageTitle>
 	    <div className="flex flex-wrap gap-2">
 	      {/* TODO: 局所出力を可能にする */}
 	      {/* <a
@@ -431,25 +447,25 @@ const MaterialListPage: FC = () => {
 			      dark:border-sky-800 dark:bg-sky-950 dark:text-sky-100">
 		<span>
 		  {tagScope.tag.name}
-		  {tagScope.includeDescendants ? ' 配下の素材を表示中' : ' の素材を表示中'}
+		  {label (tagScope.includeDescendants ? 'descendantScope' : 'tagScope')}
 		</span>
 		<PrefetchLink
 		    to={clearedTagSelectionPath (location.search, materialFilter)}
 		    className="font-medium underline underline-offset-2
 			       text-sky-700 dark:text-sky-300">
-		  タグ選択を解除
+		  {label ('clearTag')}
 		</PrefetchLink>
 	      </div>)}
 	  {(tagId != null && tagScope == null) && (
 	      <div className="flex flex-wrap items-center gap-3 rounded-lg border
 			      border-amber-200 bg-amber-50 px-4 py-3 text-sm text-amber-900
 			      dark:border-amber-800 dark:bg-amber-950 dark:text-amber-100">
-		<span>選択中タグが見つかりません．</span>
+		<span>{label ('tagMissing')}</span>
 		<PrefetchLink
 		    to={clearedTagSelectionPath (location.search, materialFilter)}
 		    className="font-medium underline underline-offset-2
 			       text-amber-800 dark:text-amber-200">
-		  タグ選択を解除
+		  {label ('clearTag')}
 		</PrefetchLink>
 	      </div>)}
 
@@ -457,7 +473,7 @@ const MaterialListPage: FC = () => {
 	      <PrefetchLink
 		  to={`/materials?material_filter=${ materialFilter }`}
 		  className="text-sm text-sky-700 underline underline-offset-2 dark:text-sky-300">
-		素材検索トップへ戻る
+		{label ('searchTop')}
 	      </PrefetchLink>)}
 
 	  <form
@@ -466,44 +482,49 @@ const MaterialListPage: FC = () => {
 			 text-stone-900 dark:border-stone-700 dark:bg-stone-900
 			 dark:text-stone-100">
 	    <div className="space-y-3">
-	      <FormField label="検索">
+	      <FormField label={label ('common:search')}>
 		{({ invalid }) => (
 		    <input
 			type="search"
 			value={q}
 			onChange={e => setQ (e.target.value)}
-			placeholder="タグ名 / URL / ファイル名"
+			placeholder={message ('searchPlaceholder').text}
+			lang={message ('searchPlaceholder').language}
 			className={inputClass (invalid)}/>)}
 	      </FormField>
 
-	      <FormField label="タグ状態">
+	      <FormField label={label ('tagState')}>
 		{({ invalid }) => (
 		    <select
 			value={tagStateInput}
 			onChange={e => setTagStateInput (
 			    e.target.value as MaterialIndexTagState)}
 			className={inputClass (invalid)}>
-		      <option value="all">すべて</option>
-		      <option value="tagged">タグあり</option>
+		      <option value="all" lang={message ('mediaFilter.all').language}>
+			{message ('mediaFilter.all').text}
+		      </option>
+		      <option value="tagged" lang={message ('tagged').language}>
+			{message ('tagged').text}
+		      </option>
 		      <option value="untagged"></option>
 		    </select>)}
 	      </FormField>
 
-	      <FormField label="メディア">
+	      <FormField label={label ('mediaLabel')}>
 		{({ invalid }) => (
 		    <select
 			value={mediaKindInput}
 			onChange={e => setMediaKindInput (
 			    e.target.value as MaterialIndexMediaKind)}
 			className={inputClass (invalid)}>
-		      {Object.entries (MEDIA_FILTER_LABELS).map (([value, label]) => (
-			  <option key={value} value={value}>
-			    {label}
+		      {Object.entries (MEDIA_FILTER_LABELS).map (([value, key]) => (
+			  <option key={value} value={value} lang={message (key).language}>
+			    {message (key).text}
 			  </option>))}
 		    </select>)}
 	      </FormField>
 
-	      <FormField label="作成日時">
+	      <FormField label={label ('sort.created_at')}>
 		{() => (
 		    <div className="flex flex-wrap items-center gap-2">
 		      <DateTimeField value={createdFrom ?? undefined} onChange={setCreatedFrom}/>
@@ -512,7 +533,7 @@ const MaterialListPage: FC = () => {
 		    </div>)}
 	      </FormField>
 
-	      <FormField label="更新日時">
+	      <FormField label={label ('sort.updated_at')}>
 		{() => (
 		    <div className="flex flex-wrap items-center gap-2">
 		      <DateTimeField value={updatedFrom ?? undefined} onChange={setUpdatedFrom}/>
@@ -527,7 +548,7 @@ const MaterialListPage: FC = () => {
 		  type="submit"
 		  className="rounded bg-sky-600 px-4 py-2 text-white hover:bg-sky-700
 			     dark:bg-sky-500 dark:text-stone-950 dark:hover:bg-sky-400">
-		検索
+		{label ('common:search')}
 	      </button>
 	    </div>
 	  </form>
@@ -546,7 +567,7 @@ const MaterialListPage: FC = () => {
 			      : [
 				  'border-stone-300 bg-white text-stone-900 dark:border-stone-700',
 				  'dark:bg-stone-900 dark:text-stone-100'])}>
-		アイコン
+		{label ('cardView')}
 	      </button>
 		      <button
 			  type="button"
@@ -560,7 +581,7 @@ const MaterialListPage: FC = () => {
 			      : [
 				  'border-stone-300 bg-white text-stone-900 dark:border-stone-700',
 				  'dark:bg-stone-900 dark:text-stone-100'])}>
-		詳細
+		{label ('listView')}
 	      </button>
 	    </div>
 
@@ -569,34 +590,38 @@ const MaterialListPage: FC = () => {
 		  value={sort}
 		  onChange={e => updateQuery ({ sort: e.target.value, page: '1' })}
 		  className={inputClass (false, 'w-auto')}>
-		{Object.entries (SORT_LABELS).map (([value, label]) => (
-		    <option key={value} value={value}>
-		      {label}
+		{Object.entries (SORT_LABELS).map (([value, key]) => (
+		    <option key={value} value={value} lang={message (key).language}>
+		      {message (key).text}
 		    </option>))}
 	      </select>
 	      <select
 		  value={direction}
 		  onChange={e => updateQuery ({ direction: e.target.value, page: '1' })}
 		  className={inputClass (false, 'w-auto')}>
-		<option value="desc">降順</option>
-		<option value="asc">昇順</option>
+		<option value="desc" lang={message ('descending').language}>
+		  {message ('descending').text}
+		</option>
+		<option value="asc" lang={message ('ascending').language}>
+		  {message ('ascending').text}
+		</option>
 	      </select>
 	    </div>
 	  </div>
 
-	  {isLoading && <p>Loading...</p>}
+	  {isLoading && <p>{label ('common:loading')}</p>}
 	  {isError && (
-	      <p className="text-red-600 dark:text-red-300">素材一覧の取得に失敗しました．</p>)}
+	      <p className="text-red-600 dark:text-red-300">{label ('listError')}</p>)}
 	  {(!isLoading && !isError && materials.length === 0) && (
 	      <p>
-		素材はありません。
+		{label ('empty')}
 		{(tagScope && ['character', 'material'].includes (tagScope.tag.category)) && (
 		    <>
 		      <PrefetchLink
 			  to={materialNewPath (tagScope.tag.name, location.pathname + location.search)}
 			  className="font-medium underline underline-offset-2
 				     text-sky-700 dark:text-sky-300">
-			追加してください
+			{label ('pleaseAdd')}
 		      </PrefetchLink>。
 		    </>)}
 	      </p>)}
diff --git a/frontend/src/pages/materials/MaterialNewPage.tsx b/frontend/src/pages/materials/MaterialNewPage.tsx
index 3c60339..342f950 100644
--- a/frontend/src/pages/materials/MaterialNewPage.tsx
+++ b/frontend/src/pages/materials/MaterialNewPage.tsx
@@ -18,6 +18,7 @@ import { unlocalisedPath } from '@/lib/locales'
 import { materialsKeys } from '@/lib/queryKeys'
 import { inputClass } from '@/lib/utils'
 import { useValidationErrors } from '@/lib/useValidationErrors'
+import { useUITranslation } from '@/lib/useUITranslation'
 
 import type { FC } from 'react'
 
@@ -26,6 +27,7 @@ type MaterialFormField = 'tag' | 'file' | 'url' | 'exportPaths'
 
 const MaterialNewPage: FC = () => {
   const locale = useLocale ()
+  const { message, label } = useUITranslation ('materials')
   const qc = useQueryClient ()
   const location = useLocation ()
   const query = new URLSearchParams (location.search)
@@ -59,12 +61,12 @@ const MaterialNewPage: FC = () => {
       },
       onSuccess: async () => {
 	await qc.invalidateQueries ({ queryKey: materialsKeys.root })
-	toast ({ title: '送信成功!' })
+	toast ({ title: label ('sent') })
 	navigate (safeReturnTo || '/materials')
       },
       onError: error => {
 	applyValidationError (error)
-	toast ({ title: '送信失敗……', description: '入力を見直してください．' })
+	toast ({ title: label ('sendFailed'), description: label ('shared:messages.reviewInput') })
       }})
 
   const handleSubmit = () => {
@@ -75,15 +77,15 @@ const MaterialNewPage: FC = () => {
   return (
       <MainArea>
 	<Helmet>
-	  <title>{`素材追加 | ${ SITE_TITLE }`}</title>
+	  <title>{message ('newTitle').text} | {SITE_TITLE}</title>
 	</Helmet>
 
 	<Form>
-	  <PageTitle>素材追加</PageTitle>
+	  <PageTitle>{label ('newTitle')}</PageTitle>
 	  <FieldError messages={baseErrors}/>
 
 	  {/* タグ */}
-	   <FormField label="タグ" messages={fieldErrors.tag}>
+	   <FormField label={label ('navigation:tags')} messages={fieldErrors.tag}>
 	    {({ describedBy, invalid }) => (
 		<TagInput
 		    describedBy={describedBy}
@@ -93,7 +95,7 @@ const MaterialNewPage: FC = () => {
 	  </FormField>
 
 	  {/* ファイル */}
-	  <FormField label="ファイル" messages={fieldErrors.file}>
+	  <FormField label={label ('file')} messages={fieldErrors.file}>
 	    {({ describedBy, invalid }) => (
 		<>
 		  <input
@@ -110,7 +112,8 @@ const MaterialNewPage: FC = () => {
 		      (/image\/.*/.test (file.type) && (
 			  <img
 			      src={filePreview}
-			      alt="preview"
+			      alt={message ('preview').text}
+			      lang={message ('preview').language}
 			      className="mt-2 max-h-48 rounded border"/>))
 		      || (/video\/.*/.test (file.type) && (
 			  <video
@@ -124,13 +127,13 @@ const MaterialNewPage: FC = () => {
 			      className="mt-2 max-h-48"/>))
 		      || (
 			  <p className="text-red-600 dark:text-red-400">
-			    その形式のファイルには対応していません．
+			    {label ('unsupportedFile')}
 			  </p>))}
 		</>)}
 	  </FormField>
 
 	  {/* 参考 URL */}
-	  <FormField label="参考 URL" messages={fieldErrors.url}>
+	  <FormField label={label ('referenceUrl')} messages={fieldErrors.url}>
 	    {({ describedBy, invalid }) => (
 		<input
 		    type="url"
@@ -142,14 +145,15 @@ const MaterialNewPage: FC = () => {
 	  </FormField>
 
 	  <FormField
-	      label="ZIP 出力パス"
+	      label={label ('exportPath')}
 	      messages={fieldErrors.exportPaths}>
 	    {({ describedBy, invalid }) => (
 		<input
 		    type="text"
 		    value={exportPath}
 		    onChange={e => setExportPath (e.target.value)}
-		    placeholder="伊地知ニジカ/表情/泣き.png"
+		    placeholder={message ('exportPlaceholder').text}
+		    lang={message ('exportPlaceholder').language}
 		    aria-describedby={describedBy}
 		    aria-invalid={invalid}
 		    className={inputClass (invalid)}/>)}
@@ -160,7 +164,7 @@ const MaterialNewPage: FC = () => {
 	      onClick={handleSubmit}
 	      className="px-4 py-2 bg-blue-600 text-white rounded disabled:bg-gray-400"
 	      disabled={createMutation.isPending}>
-	    追加
+	    {label ('shared:actions.add')}
 	  </Button>
 	</Form>
       </MainArea>)
diff --git a/frontend/src/pages/materials/MaterialSyncSuppressionsPage.tsx b/frontend/src/pages/materials/MaterialSyncSuppressionsPage.tsx
index b155de9..57b9d5a 100644
--- a/frontend/src/pages/materials/MaterialSyncSuppressionsPage.tsx
+++ b/frontend/src/pages/materials/MaterialSyncSuppressionsPage.tsx
@@ -11,19 +11,20 @@ import { toast } from '@/components/ui/use-toast'
 import { SITE_TITLE } from '@/config'
 import { createMaterialSyncSuppression, fetchMaterialSyncSuppressions } from '@/lib/materials'
 import { materialsKeys } from '@/lib/queryKeys'
-import { dateString, inputClass } from '@/lib/utils'
+import { localisedDateString, inputClass } from '@/lib/utils'
+import { useUITranslation } from '@/lib/useUITranslation'
 
 import type { FC, FormEvent } from 'react'
 
 import type { MaterialSyncSuppressionSourceKind } from '@/types'
 
 const SOURCE_KIND_LABELS: Record<MaterialSyncSuppressionSourceKind, string> = {
-    uri:               'URI',
-    google_drive_path: 'Google Drive ファイル',
-    google_drive_path_prefix: 'Google Drive フォルダ',
-    google_drive_file: 'Google Drive ファイル Id.',
-    legacy_drive_path: '汎用ファイル',
-    legacy_drive_path_prefix: '汎用フォルダ' }
+    uri: 'suppressions.sources.uri',
+    google_drive_path: 'suppressions.sources.google_drive_path',
+    google_drive_path_prefix: 'suppressions.sources.google_drive_path_prefix',
+    google_drive_file: 'suppressions.sources.google_drive_file',
+    legacy_drive_path: 'suppressions.sources.legacy_drive_path',
+    legacy_drive_path_prefix: 'suppressions.sources.legacy_drive_path_prefix' }
 
 const REASONS = [
     'copyright_high_risk',
@@ -37,23 +38,9 @@ const REASONS = [
 
 type MaterialSyncSuppressionReason = typeof REASONS[number]
 
-const REASON_NAMES: Record<MaterialSyncSuppressionReason, string> = {
-    ['copyright_high_risk']: '著作権への懸念',
-    ['copyright_takedown']: '著作者からの申出',
-    ['adult_or_sensitive']: '成人向け',
-    ['personal_information']: '個人情報',
-    ['malware_or_dangerous_file']: '危険なソフトウェア',
-    ['duplicate_or_low_quality']: '重複',
-    ['source_owner_request']: '同期元管理者からの申出',
-    ['other']: 'その他' } as const
-
-
-const reasonName = (reason: string): string =>
-    REASON_NAMES[reason as MaterialSyncSuppressionReason] ?? reason
-
-
 const MaterialSyncSuppressionsPage: FC = () => {
   const locale = useLocale ()
+  const { message, label } = useUITranslation ('materials')
   const qc = useQueryClient ()
   const [sourceKind, setSourceKind] =
       useState<MaterialSyncSuppressionSourceKind> ('uri')
@@ -80,10 +67,10 @@ const MaterialSyncSuppressionsPage: FC = () => {
 	setSourceUri ('')
 	setDrivePath ('')
 	setDriveFileId ('')
-	toast ({ title: '同期元抑止を登録しました' })
+	toast ({ title: label ('suppressions.registered') })
       },
       onError: () => {
-	toast ({ title: '同期元抑止の登録に失敗しました' })
+	toast ({ title: label ('suppressions.registerFailed') })
       }})
 
   const handleSubmit = (event: FormEvent) => {
@@ -96,11 +83,11 @@ const MaterialSyncSuppressionsPage: FC = () => {
   return (
       <MainArea>
 	<Helmet>
-	  <title>{`素材同期抑止 | ${ SITE_TITLE }`}</title>
+	  <title>{message ('suppressions.title').text} | {SITE_TITLE}</title>
 	</Helmet>
 
 	<div className="space-y-5">
-	  <PageTitle>同期抑止</PageTitle>
+	  <PageTitle>{label ('suppressions.heading')}</PageTitle>
 
 	  <form
 	      onSubmit={handleSubmit}
@@ -108,21 +95,21 @@ const MaterialSyncSuppressionsPage: FC = () => {
 			 text-stone-900 dark:border-stone-700 dark:bg-stone-900
 			 dark:text-stone-100">
 	    <div className="space-y-3">
-	      <FormField label="同期元種別">
+	      <FormField label={label ('suppressions.sourceKind')}>
 		{({ invalid }) => (
 		    <select
 			value={sourceKind}
 			onChange={e => setSourceKind (
 			    e.target.value as MaterialSyncSuppressionSourceKind)}
 			className={inputClass (invalid)}>
-		      {Object.entries (SOURCE_KIND_LABELS).map (([value, label]) => (
-			  <option key={value} value={value}>
-			    {label}
+		      {Object.entries (SOURCE_KIND_LABELS).map (([value, key]) => (
+			  <option key={value} value={value} lang={message (key).language}>
+			    {message (key).text}
 			  </option>))}
 		    </select>)}
 	      </FormField>
 
-	      <FormField label="同期元 URI">
+	      <FormField label={label ('suppressions.sourceUri')}>
 		{({ invalid }) => (
 		    <input
 			type="text"
@@ -131,7 +118,7 @@ const MaterialSyncSuppressionsPage: FC = () => {
 			className={inputClass (invalid)}/>)}
 	      </FormField>
 
-	      <FormField label="Google Drive パス">
+	      <FormField label={label ('suppressions.drivePath')}>
 		{({ invalid }) => (
 		    <input
 			type="text"
@@ -140,7 +127,7 @@ const MaterialSyncSuppressionsPage: FC = () => {
 			className={inputClass (invalid)}/>)}
 	      </FormField>
 
-	      <FormField label="Google Drive ファイル Id.">
+	      <FormField label={label ('suppressions.driveFileId')}>
 		{({ invalid }) => (
 		    <input
 			type="text"
@@ -149,15 +136,16 @@ const MaterialSyncSuppressionsPage: FC = () => {
 			className={inputClass (invalid)}/>)}
 	      </FormField>
 
-	      <FormField label="事由">
+	      <FormField label={label ('suppressions.reason')}>
 		{({ invalid }) => (
 		    <select
 			value={reason}
 			onChange={e => setReason (e.target.value as MaterialSyncSuppressionReason)}
 			className={inputClass (invalid)}>
 		      {REASONS.map (value => (
-			  <option key={value} value={value}>
-			    {REASON_NAMES[value]}
+			  <option key={value} value={value}
+			      lang={message (`suppressions.reasons.${value}`).language}>
+			    {message (`suppressions.reasons.${value}`).text}
 			  </option>))}
 		    </select>)}
 	      </FormField>
@@ -168,14 +156,14 @@ const MaterialSyncSuppressionsPage: FC = () => {
 		className="mt-4 rounded bg-blue-600 px-4 py-2 text-white
 			   disabled:bg-gray-400"
 		disabled={createMutation.isPending}>
-	      登録
+	      {label ('suppressions.register')}
 	    </Button>
 	  </form>
 
-	  {isLoading && <p>Loading...</p>}
+	  {isLoading && <p>{label ('common:loading')}</p>}
 	  {isError && (
 	      <p className="text-red-600 dark:text-red-300">
-		同期元抑止一覧の取得に失敗しました．
+		{label ('suppressions.error')}
 	      </p>)}
 
 	  <div className="space-y-3">
@@ -186,14 +174,20 @@ const MaterialSyncSuppressionsPage: FC = () => {
 			       text-stone-900 shadow-sm dark:border-stone-700
 			       dark:bg-stone-900 dark:text-stone-100">
 		  <div className="font-medium">
-		    {SOURCE_KIND_LABELS[suppression.sourceKind]}
+		    {label (SOURCE_KIND_LABELS[suppression.sourceKind])}
 		  </div>
 		  <div className="break-all text-sm text-stone-700 dark:text-stone-300">
 		    {suppression.normalizedSourceKey}
 		  </div>
 		  <div className="mt-2 text-sm text-stone-600 dark:text-stone-400">
-		    事由: {reasonName (suppression.reason)} /
-		    登録: {dateString (suppression.createdAt)}
+		    {label ('suppressions.reasonPrefix')}
+		    {REASONS.includes (suppression.reason as MaterialSyncSuppressionReason)
+		     ? label (`suppressions.reasons.${suppression.reason}`)
+		     : suppression.reason} /{' '}
+		    {label ('suppressions.registeredPrefix')}
+		    <time dateTime={suppression.createdAt} lang={locale}>
+		      {localisedDateString (suppression.createdAt, locale)}
+		    </time>
 		  </div>
 		</article>))}
 	  </div>
diff --git a/frontend/src/pages/theatres/TheatreDetailPage.tsx b/frontend/src/pages/theatres/TheatreDetailPage.tsx
index 550cc99..ded594f 100644
--- a/frontend/src/pages/theatres/TheatreDetailPage.tsx
+++ b/frontend/src/pages/theatres/TheatreDetailPage.tsx
@@ -8,13 +8,14 @@ import ErrorScreen from '@/components/ErrorScreen'
 import PostEditForm from '@/components/PostEditForm'
 import PostEmbed from '@/components/PostEmbed'
 import PrefetchLink from '@/components/PrefetchLink'
+import LocalisedText from '@/components/LocalisedText'
 import TagLink from '@/components/TagLink'
 import FieldError from '@/components/common/FieldError'
-import { useDialogue } from '@/components/dialogues/DialogueProvider'
+import useDialogue from '@/lib/dialogues/useDialogue'
 import SidebarComponent from '@/components/layout/SidebarComponent'
 import { Button } from '@/components/ui/button'
 import { SITE_TITLE } from '@/config'
-import { CATEGORIES, CATEGORY_NAMES } from '@/consts'
+import { CATEGORIES } from '@/consts'
 import { apiDelete, apiGet, apiPatch, apiPost, apiPut, isApiError } from '@/lib/api'
 import { clientAnimationTransition,
 	 clientScrollBehaviour } from '@/lib/clientAnimation'
@@ -27,8 +28,9 @@ import {
 } from '@/lib/settings'
 import { useClientBehaviourSettings } from '@/lib/useClientBehaviourSettings'
 import { canEditContent } from '@/lib/users'
-import { cn, dateString, inputClass } from '@/lib/utils'
+import { cn, localisedDateString, inputClass } from '@/lib/utils'
 import { useValidationErrors } from '@/lib/useValidationErrors'
+import { useUITranslation } from '@/lib/useUITranslation'
 
 import type { FC, FormEvent, ReactNode } from 'react'
 
@@ -65,48 +67,13 @@ const MIN_MAIN_WIDTH = 360
 const SIDEBAR_GAP_WIDTH = 16
 
 const LAYOUT_LABELS: Record<TheatreLayoutMode, string> = {
-    threeColumns:   '3 列',
-    tagsBottom:     '2 列 A 型',
-    commentsBottom: '2 列 B 型' }
+    threeColumns: 'layouts.threeColumns',
+    tagsBottom: 'layouts.tagsBottom',
+    commentsBottom: 'layouts.commentsBottom' }
 
 const TAG_FLOW_LABELS: Record<TagFlow, string> = {
-    vertical:   '縦並び',
-    horizontal: '横並び' }
-
-
-const userName = (user: Pick<User, 'id' | 'name'> | null | undefined): string =>
-    user ? (user.name || `名もなきニジラー（#${ user.id }）`) : '運営'
-
-
-const commentBox = (
-    comment: TheatreComment,
-    programme: TheatreProgramme | null = null): ReactNode[] =>
-    [(
-	<div key={`${ comment.no }-content`} className="w-full">
-	  {comment.deleted
-	   ? <span className="text-sm font-bold">削除されました．</span>
-	   : comment.content}
-	</div>),
-     (
-	<div key={`${ comment.no }-user`} className="w-full text-sm text-right">
-	  by {userName (comment.user)}
-	</div>),
-     (
-	<div key={`${ comment.no }-createdAt`} className="w-full text-sm text-right">
-	  {dateString (comment.createdAt)}
-	</div>),
-     (
-	<div
-	    key={`${ comment.no }-post`}
-	    className="mt-1 w-full text-xs text-zinc-500 dark:text-zinc-400">
-	  {programme && (
-	      <>
-		<PrefetchLink to={`/posts/${ programme.post.id }`} className="font-bold hover:underline">
-		  {programme.post.title || programme.post.url}
-		</PrefetchLink>
-		&thinsp;へのコメント
-	      </>)}
-	</div>)]
+    vertical: 'flows.vertical',
+    horizontal: 'flows.horizontal' }
 
 
 const compareTagName = (a: Tag, b: Tag): number =>
@@ -176,6 +143,7 @@ const renderReadonlyTagTree = (
 
 const TagList: FC<{ tags: Tag[]; compact?: boolean; flow?: TagFlow }> = (
     { tags, compact, flow = 'vertical' }) => {
+  const { label } = useUITranslation ()
   const horizontalGrouped = tagsByCategory (flattenTags (tags))
   const verticalGrouped = tagsByCategory (tags)
 
@@ -200,7 +168,7 @@ const TagList: FC<{ tags: Tag[]; compact?: boolean; flow?: TagFlow }> = (
 	  return (
 	      <div key={cat}>
 		<div className="mb-1 shrink-0 text-xs font-bold text-zinc-500 dark:text-zinc-400">
-		  {CATEGORY_NAMES[cat]}
+		  {label (`categories.${cat}`)}
 		</div>
 		<ul className={cn ('space-y-1', compact && 'text-sm')}>
 		  {rows.flatMap (tag =>
@@ -217,6 +185,36 @@ type Props = { user: User | null }
 
 const TheatreDetailPage: FC<Props> = ({ user }: Props) => {
   const locale = useLocale ()
+  const { message, label } = useUITranslation ('theatres')
+  const userName = (entry: Pick<User, 'id' | 'name'> | null | undefined): ReactNode =>
+      entry ? (entry.name || label ('history:anonymous', { id: entry.id })) : label ('staff')
+  const commentBox = (
+      comment: TheatreComment,
+      programme: TheatreProgramme | null = null,
+  ): ReactNode[] => [
+      (<div key={`${comment.no}-content`} className="w-full">
+	{comment.deleted
+	 ? <span className="text-sm font-bold">{label ('deleted')}</span>
+	 : comment.content}
+      </div>),
+      (<div key={`${comment.no}-user`} className="w-full text-sm text-right">
+	{label ('authorPrefix')}{userName (comment.user)}
+      </div>),
+      (<div key={`${comment.no}-createdAt`} className="w-full text-sm text-right">
+	<LocalisedText language={locale}>
+	  {localisedDateString (comment.createdAt, locale)}
+	</LocalisedText>
+      </div>),
+      (<div key={`${comment.no}-post`}
+	  className="mt-1 w-full text-xs text-zinc-500 dark:text-zinc-400">
+	{programme && (
+	    <>
+	      <PrefetchLink to={`/posts/${programme.post.id}`} className="font-bold hover:underline">
+		{programme.post.title || programme.post.url}
+	      </PrefetchLink>
+	      {label ('commentSuffix')}
+	    </>)}
+      </div>)]
   const behaviourSettings = useClientBehaviourSettings ()
   const animationMode = behaviourSettings.animation ?? 'normal'
   const layoutTransition = clientAnimationTransition (
@@ -644,7 +642,9 @@ const TheatreDetailPage: FC<Props> = ({ user }: Props) => {
   }
 
   const skipVote = theatreInfo.skipVote
-  const theatreTitle = theatre?.name ? `上映会場『${ theatre.name }』` : '上映会場'
+  const theatreTitle = theatre?.name
+      ? message ('namedTitle', { name: theatre.name })
+      : message ('title')
   const postTags = post?.tags ?? []
   const programmesAsc = useMemo (
       () => [...programmes].sort (
@@ -693,7 +693,7 @@ const TheatreDetailPage: FC<Props> = ({ user }: Props) => {
   const tagPanel = (
       <section className="rounded border-zinc-300 p-4 dark:border-zinc-800">
 	<div className="mb-3 flex items-center justify-between gap-3">
-	  <h2 className="font-bold">タグ</h2>
+	  <h2 className="font-bold">{label ('navigation:tags')}</h2>
 	  {layoutMode === 'tagsBottom' && (
 	      <div className="hidden gap-2 md:flex">
 		{(Object.keys (TAG_FLOW_LABELS) as TagFlow[]).map (flow => (
@@ -703,23 +703,24 @@ const TheatreDetailPage: FC<Props> = ({ user }: Props) => {
 			size="sm"
 			variant={tagFlow === flow ? 'default' : 'outline'}
 			onClick={() => changeTagFlow (flow)}>
-		      {TAG_FLOW_LABELS[flow]}
+		      {label (TAG_FLOW_LABELS[flow])}
 		    </Button>))}
 	      </div>)}
 	</div>
 	{postTags.length === 0
-	 ? <div className="text-sm text-zinc-500">タグはありません。</div>
+	 ? <div className="text-sm text-zinc-500">{label ('noTags')}</div>
 	 : <TagList tags={postTags} flow={layoutMode === 'tagsBottom' ? tagFlow : 'vertical'}/>}
       </section>)
 
   const commentsPanel = (
       <section className="rounded border-zinc-300 p-4 dark:border-zinc-800">
-	<h2 className="mb-3 font-bold">コメント</h2>
+	<h2 className="mb-3 font-bold">{label ('comments')}</h2>
 	<form onSubmit={handleCommentSubmit}>
 	  <input
 	      className={inputClass ((fieldErrors.content ?? []).length > 0)}
 	      type="text"
-	      placeholder="ここにコメントを入力"
+	      placeholder={message ('commentPlaceholder').text}
+	      lang={message ('commentPlaceholder').language}
 	      value={content}
 	      onChange={e => setContent (e.target.value)}
 	      disabled={sending}/>
@@ -743,18 +744,21 @@ const TheatreDetailPage: FC<Props> = ({ user }: Props) => {
 			  className="absolute left-1 top-1 hidden rounded px-1 text-red-600
 				     hover:bg-red-100 group-hover:inline-block dark:text-red-300
 				     dark:hover:bg-red-950"
-			  aria-label="コメントを削除"
+			  aria-label={message ('deleteComment').text}
+			  lang={message ('deleteComment').language}
 			  onClick={async e => {
 			    e.stopPropagation ()
 
 			    if (!(await dialogue.confirm ({
-				title: 'このコメントを削除しますか?',
+				title: label ('confirmDelete'),
 				description: (
 				    <div className="my-3 w-120 rounded border border-black p-2
 						    dark:border-white">
 				      {commentBox (comment, commentProgramme)}
 				    </div>),
-				confirmText: '削除',
+				confirmText: label ('delete'),
+				cancelText: label ('shared:actions.cancel'),
+				closeLabel: label ('settings:actions.close'),
 				variant: 'danger' })))
 			      return
 
@@ -770,23 +774,24 @@ const TheatreDetailPage: FC<Props> = ({ user }: Props) => {
 
   const participantsPanel = (
       <section className="rounded border-zinc-300 p-4 dark:border-zinc-800">
-	<h2 className="mb-3 font-bold">参加者</h2>
+	<h2 className="mb-3 font-bold">{label ('participants')}</h2>
 	<div className="space-y-1">
 	  {theatreInfo.watchingUsers.map (watchingUser => (
 	      <div key={watchingUser.id} className="flex justify-between gap-2 text-sm">
 		<span>{userName (watchingUser)}</span>
-		{watchingUser.id === user?.id && <span className="text-zinc-500">お前</span>}
+		{watchingUser.id === user?.id && (
+		    <span className="text-zinc-500">{label ('navigation:currentUser')}</span>)}
 	      </div>))}
 	</div>
       </section>)
 
   const historyPanel = (
       <section className="rounded border-zinc-300 p-4 dark:border-zinc-800">
-	<h2 className="mb-3 font-bold">再生履歴</h2>
+	<h2 className="mb-3 font-bold">{label ('history')}</h2>
 	<div className="rounded border border-zinc-300 dark:border-zinc-800 max-h-72
 			overflow-y-auto">
 	  {programmes.length === 0
-	   ? <div className="text-sm text-zinc-500">まだ履歴はありません。</div>
+	   ? <div className="text-sm text-zinc-500">{label ('emptyHistory')}</div>
 	   : (
 	      programmes.map (programme => (
 		  <div
@@ -799,7 +804,9 @@ const TheatreDetailPage: FC<Props> = ({ user }: Props) => {
 		      {programme.post.title || programme.post.url}
 		    </PrefetchLink>
 		    <div className="text-xs text-zinc-500">
-		      {dateString (programme.createdAt)}
+		      <LocalisedText language={locale}>
+			{localisedDateString (programme.createdAt, locale)}
+		      </LocalisedText>
 		    </div>
 		  </div>)))}
 	</div>
@@ -808,18 +815,18 @@ const TheatreDetailPage: FC<Props> = ({ user }: Props) => {
   const weightsPanel = (
       <section className="rounded border-zinc-300 p-4 dark:border-zinc-800">
 	<div className="mb-3 flex items-center justify-between gap-3">
-	  <h2 className="font-bold">抽選重み</h2>
+	  <h2 className="font-bold">{label ('weights')}</h2>
 	  <Button type="button" variant="outline" size="sm" onClick={() => void refreshWeights ()}>
-	    更新
+	    {label ('shared:actions.update')}
 	  </Button>
 	</div>
 
 	<div className="mx-4 grid gap-16 xl:grid-cols-3">
 	  <div>
-	    <h3 className="mb-2 text-sm font-bold">出にくいタグ</h3>
+	    <h3 className="mb-2 text-sm font-bold">{label ('unlikelyTags')}</h3>
 	    <div className="space-y-1 text-sm">
 	      {weights.tagPenalties.length === 0
-	       ? <div className="text-zinc-500">まだ減点はありません。</div>
+	       ? <div className="text-zinc-500">{label ('emptyPenalties')}</div>
 	       : (
 		  weights.tagPenalties.slice (0, 12).map (row => (
 		      <div
@@ -835,12 +842,12 @@ const TheatreDetailPage: FC<Props> = ({ user }: Props) => {
 	  </div>
 
 	  <div>
-	    <h3 className="mb-2 text-sm font-bold">出にくい候補</h3>
+	    <h3 className="mb-2 text-sm font-bold">{label ('unlikelyPosts')}</h3>
 	    <WeightRows rows={weights.lightestPosts}/>
 	  </div>
 
 	  <div>
-	    <h3 className="mb-2 text-sm font-bold">出やすい候補</h3>
+	    <h3 className="mb-2 text-sm font-bold">{label ('likelyPosts')}</h3>
 	    <WeightRows rows={weights.heaviestPosts}/>
 	  </div>
 	</div>
@@ -854,7 +861,7 @@ const TheatreDetailPage: FC<Props> = ({ user }: Props) => {
 		     md:overflow-hidden dark:bg-zinc-950 dark:text-zinc-50">
 	<Helmet>
 	  <meta name="robots" content="noindex"/>
-	  {theatre && <title>{`${ theatreTitle } | ${ SITE_TITLE }`}</title>}
+	  {theatre && <title>{theatreTitle.text} | {SITE_TITLE}</title>}
 	</Helmet>
 
 	<div
@@ -882,9 +889,13 @@ const TheatreDetailPage: FC<Props> = ({ user }: Props) => {
 		<div className="flex flex-wrap items-center justify-between gap-3
 				border-zinc-200 px-4 py-3 dark:border-zinc-800">
 		  <div>
-		    <h1 className="text-lg font-bold">{theatreTitle}</h1>
+		    <h1 className="text-lg font-bold">
+		      <LocalisedText language={theatreTitle.language}>
+			{theatreTitle.text}
+		      </LocalisedText>
+		    </h1>
 		    <p className="text-sm text-zinc-500 dark:text-zinc-400">
-		      同接 {theatreInfo.watchingUsers.length} 人
+		      {label ('watching', { count: theatreInfo.watchingUsers.length })}
 		    </p>
 		  </div>
 
@@ -897,7 +908,7 @@ const TheatreDetailPage: FC<Props> = ({ user }: Props) => {
 			      size="sm"
 			      variant={layoutMode === mode ? 'default' : 'outline'}
 			      onClick={() => changeLayoutMode (mode)}>
-			    {LAYOUT_LABELS[mode]}
+			    {label (LAYOUT_LABELS[mode])}
 			  </Button>))}
 		    </div>
 
@@ -907,7 +918,7 @@ const TheatreDetailPage: FC<Props> = ({ user }: Props) => {
 			variant={skipVote.voted ? 'secondary' : 'destructive'}
 			disabled={loading || !(post)}
 			onClick={handleSkipVote}>
-		      {skipVote.voted ? 'スキップ取消' : 'スキップ'}
+		      {skipVote.voted ? label ('cancelSkip') : label ('shared:actions.skip')}
 		      {` ${ skipVote.votesCount } / ${ skipVote.requiredCount }`}
 		    </Button>
 
@@ -924,14 +935,14 @@ const TheatreDetailPage: FC<Props> = ({ user }: Props) => {
 			  onPlaybackChange={syncPlaybackTime}
 			  onError={handlePlaybackError}/>) : (
 		      <div className="grid min-h-72 place-items-center text-zinc-400">
-			{loading ? '次の投稿を選んでゐます……' : '上映待機中'}
+			{label (loading ? 'selecting' : 'waiting')}
 		      </div>)}
 		</div>
 
 		<div className="flex flex-wrap items-center justify-between gap-3 px-4 py-3">
 		  <div className="min-w-0">
 		    <div className="text-xs font-bold text-zinc-500 dark:text-zinc-400">
-		      再生中
+		      {label ('playing')}
 		    </div>
 		    {post ? (
 			<PrefetchLink
@@ -939,7 +950,7 @@ const TheatreDetailPage: FC<Props> = ({ user }: Props) => {
 			    className="font-bold hover:underline">
 			  {post.title || post.url}
 			</PrefetchLink>) : (
-			<span className="text-zinc-500">未選択</span>)}
+			<span className="text-zinc-500">{label ('unselected')}</span>)}
 		  </div>
 
 		  {(post && canEditContent (user)) && (
@@ -949,7 +960,7 @@ const TheatreDetailPage: FC<Props> = ({ user }: Props) => {
 			  variant="outline"
 			  disabled={!(post)}
 			  onClick={() => post && setEditingPost (ep => ep ? null : post)}>
-			{editingPost ? '閉じる' : '編輯'}
+			{editingPost ? label ('close') : label ('shared:actions.edit')}
 		      </Button>)}
 		</div>
 	      </section>
@@ -958,14 +969,14 @@ const TheatreDetailPage: FC<Props> = ({ user }: Props) => {
 		  <section className="rounded border border-amber-300 bg-amber-50 mx-4 p-4
 				      dark:border-amber-800 dark:bg-amber-950/30">
 		    <div className="mb-3">
-		      <h2 className="font-bold">編輯中の投稿</h2>
+		      <h2 className="font-bold">{label ('editingPost')}</h2>
 		      <p className="text-sm text-amber-900 dark:text-amber-100">
 			<PrefetchLink
 			    to={`/posts/${ editingPost.id }`}
 			    className="mx-1 font-bold underline">
 			  {editingPost.title || editingPost.url}
 			</PrefetchLink>
-			を編輯中……
+			{label ('editingSuffix')}
 		      </p>
 		    </div>
 
@@ -1028,27 +1039,30 @@ const TheatreDetailPage: FC<Props> = ({ user }: Props) => {
 }
 
 
-const WeightRows: FC<{ rows: TheatrePostSelectionWeights['lightestPosts'] }> = ({ rows }) => (
-    <div className="space-y-2 text-sm">
-      {rows.length === 0
-       ? <div className="text-zinc-500">候補はありません。</div>
-       : (
-	  rows.slice (0, 8).map (row => (
-	      <div
-		  key={row.post.id}
-		  className="border-zinc-100 pt-2 first:border-t-0 first:pt-0
-			     dark:border-zinc-800">
-		<PrefetchLink
-		    to={`/posts/${ row.post.id }`}
-		    className="line-clamp-1 font-bold hover:underline">
-		  {row.post.title || row.post.url}
-		</PrefetchLink>
-		<div className="flex justify-between gap-2 text-xs text-zinc-500">
-		  <span>penalty {row.penalty}</span>
-		  <span>weight {row.weight.toFixed (3)}</span>
-		</div>
-	      </div>)))}
-    </div>)
+const WeightRows: FC<{ rows: TheatrePostSelectionWeights['lightestPosts'] }> = ({ rows }) => {
+  const { label } = useUITranslation ('theatres')
+  return (
+      <div className="space-y-2 text-sm">
+	{rows.length === 0
+	 ? <div className="text-zinc-500">{label ('emptyPosts')}</div>
+	 : (
+	    rows.slice (0, 8).map (row => (
+		<div
+		    key={row.post.id}
+		    className="border-zinc-100 pt-2 first:border-t-0 first:pt-0
+			       dark:border-zinc-800">
+		  <PrefetchLink
+		      to={`/posts/${ row.post.id }`}
+		      className="line-clamp-1 font-bold hover:underline">
+		    {row.post.title || row.post.url}
+		  </PrefetchLink>
+		  <div className="flex flex-wrap justify-between gap-2 text-xs text-zinc-500">
+		    <span>{label ('penalty', { value: row.penalty })}</span>
+		    <span>{label ('weight', { value: row.weight.toFixed (3) })}</span>
+		  </div>
+		</div>)))}
+      </div>)
+}
 
 
 export default TheatreDetailPage