diff --git a/backend/spec/requests/theatre_comments_spec.rb b/backend/spec/requests/theatre_comments_spec.rb
index 5f41395..78295be 100644
--- a/backend/spec/requests/theatre_comments_spec.rb
+++ b/backend/spec/requests/theatre_comments_spec.rb
@@ -80,6 +80,26 @@ RSpec.describe 'TheatreComments', type: :request do
       expect(response).to have_http_status(:ok)
       expect(response.parsed_body.map { |row| row['no'] }).to eq([3, 2, 1])
     end
+
+    it '削除済みコメントは deleted として返し、本文を隠す' do
+      comment_2.discard!
+
+      get "/theatres/#{theatre.id}/comments", params: { no_gt: 1 }
+
+      expect(response).to have_http_status(:ok)
+
+      deleted_comment = response.parsed_body.find { _1['no'] == 2 }
+      expect(deleted_comment).to include(
+        'deleted' => true,
+        'content' => nil
+      )
+
+      visible_comment = response.parsed_body.find { _1['no'] == 3 }
+      expect(visible_comment).to include(
+        'deleted' => false,
+        'content' => 'third comment'
+      )
+    end
   end
 
   describe 'POST /theatres/:theatre_id/comments' do
diff --git a/backend/spec/requests/theatre_programmes_spec.rb b/backend/spec/requests/theatre_programmes_spec.rb
index 529b583..f37fa66 100644
--- a/backend/spec/requests/theatre_programmes_spec.rb
+++ b/backend/spec/requests/theatre_programmes_spec.rb
@@ -27,5 +27,12 @@ RSpec.describe 'TheatreProgrammes', type: :request do
       expect(json.map { _1.dig('post', 'title') }).to eq(['second', 'first'])
       expect(json.first['post']).to include('id' => post_2.id, 'url' => post_2.url)
     end
+
+    it 'filters programmes by position_gt' do
+      get "/theatres/#{theatre.id}/programmes", params: { position_gt: 1 }
+
+      expect(response).to have_http_status(:ok)
+      expect(json.map { _1['position'] }).to eq([2])
+    end
   end
 end
diff --git a/backend/spec/requests/theatres_spec.rb b/backend/spec/requests/theatres_spec.rb
index 4a5a198..7fd3a0a 100644
--- a/backend/spec/requests/theatres_spec.rb
+++ b/backend/spec/requests/theatres_spec.rb
@@ -361,6 +361,24 @@ RSpec.describe 'Theatres API', type: :request do
       end
     end
 
+    it 'returns 401 when not logged in' do
+      sign_out
+
+      expect { do_request }.not_to change(TheatreSkipVote, :count)
+
+      expect(response).to have_http_status(:unauthorized)
+    end
+
+    it 'returns 422 when post_id is invalid' do
+      sign_in_as(member)
+
+      expect {
+        put "/theatres/#{theatre.id}/skip_vote", params: { post_id: 'invalid' }
+      }.not_to change(TheatreSkipVote, :count)
+
+      expect(response).to have_http_status(:unprocessable_entity)
+    end
+
     it 'records a vote and returns the current vote status before majority' do
       sign_in_as(member)
 
@@ -391,7 +409,7 @@ RSpec.describe 'Theatres API', type: :request do
 
       expect(response).to have_http_status(:ok)
       expect(json['skipped']).to eq(true)
-      expect(json['post_id']).to eq(second_niconico_post.id)
+      expect([second_niconico_post.id, youtube_post.id]).to include(json['post_id'])
 
       event = TheatreSkipEvent.last
       expect(event.post).to eq(niconico_post)
diff --git a/frontend/src/pages/theatres/TheatreDetailPage.test.tsx b/frontend/src/pages/theatres/TheatreDetailPage.test.tsx
new file mode 100644
index 0000000..3ba3409
--- /dev/null
+++ b/frontend/src/pages/theatres/TheatreDetailPage.test.tsx
@@ -0,0 +1,204 @@
+import { fireEvent, screen, waitFor } from '@testing-library/react'
+import { Route, Routes } from 'react-router-dom'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+import TheatreDetailPage from '@/pages/theatres/TheatreDetailPage'
+import { buildPost,
+	 buildTheatre,
+	 buildTheatreComment,
+	 buildTheatreInfo,
+	 buildTheatrePostSelectionWeights,
+	 buildTheatreProgramme,
+	 buildUser } from '@/test/factories'
+import { renderWithProviders } from '@/test/render'
+
+import type { ReactNode } from 'react'
+
+const api = vi.hoisted (() => ({
+  apiDelete:  vi.fn (),
+  apiGet:     vi.fn (),
+  apiPatch:   vi.fn (),
+  apiPost:    vi.fn (),
+  apiPut:     vi.fn (),
+  isApiError: vi.fn (() => false),
+}))
+
+const postsApi = vi.hoisted (() => ({
+  fetchPost: vi.fn (),
+}))
+
+const dialogue = vi.hoisted (() => ({
+  confirm: vi.fn (),
+}))
+
+vi.mock ('@/lib/api', () => api)
+vi.mock ('@/lib/posts', () => postsApi)
+vi.mock ('@/components/dialogues/DialogueProvider', () => ({
+  useDialogue: () => dialogue,
+}))
+vi.mock ('@/components/PostEmbed', () => ({
+  default: ({ post }: {
+    post: { title: string | null; url: string }
+  }) => <div>Embed:{post.title || post.url}</div>,
+}))
+vi.mock ('@/components/PostEditForm', () => ({
+  default: () => <div>Post edit form</div>,
+}))
+vi.mock ('framer-motion', () => ({
+  motion: {
+    aside: ({ children }: { children?: ReactNode }) => <aside>{children}</aside>,
+    div:   ({ children }: { children?: ReactNode }) => <div>{children}</div>,
+    main:  ({ children }: { children?: ReactNode }) => <main>{children}</main>,
+  },
+}))
+
+const currentPost = buildPost ({
+  id:    10,
+  title: '上映中の投稿',
+  url:   'https://www.nicovideo.jp/watch/sm10',
+})
+const theatre = buildTheatre ({ id: 7, name: '上映室' })
+const programme = buildTheatreProgramme ({
+  theatreId: 7,
+  position:  3,
+  post:      currentPost,
+})
+const weights = buildTheatrePostSelectionWeights ({
+  lightestPosts: [{
+    post:    currentPost,
+    penalty: 2,
+    weight:  0.5,
+    tags:    [],
+  }],
+})
+
+const renderPage = (user = buildUser ({ id: 1, role: 'member' })) =>
+  renderWithProviders (
+      <Routes>
+        <Route path="/theatres/:id" element={<TheatreDetailPage user={user}/>}/>
+      </Routes>,
+      { route: '/theatres/7' },
+  )
+
+const mockDefaultApi = () => {
+  api.apiGet.mockImplementation ((path: string) => {
+    switch (path)
+    {
+    case '/theatres/7':
+      return Promise.resolve (theatre)
+
+    case '/theatres/7/comments':
+      return Promise.resolve ([
+        buildTheatreComment ({
+          theatreId: 7,
+          no:        2,
+          user:      { id: 1, name: 'tester' },
+          content:   '視聴コメント',
+        }),
+      ])
+
+    case '/theatres/7/programmes':
+      return Promise.resolve ([programme])
+
+    case '/theatres/7/post_selection_weights':
+      return Promise.resolve (weights)
+
+    default:
+      return Promise.reject (new Error (`Unexpected GET ${ path }`))
+    }
+  })
+
+  api.apiPut.mockImplementation ((path: string) => {
+    switch (path)
+    {
+    case '/theatres/7/watching':
+      return Promise.resolve (buildTheatreInfo ({
+        postId:        currentPost.id,
+        postStartedAt: '2026-01-02T03:04:05.000Z',
+        postElapsedMs: 1_000,
+        watchingUsers: [{ id: 1, name: 'tester' }],
+        skipVote:      {
+          votesCount:         0,
+          requiredCount:      2,
+          watchingUsersCount: 1,
+          voted:              false,
+        },
+      }))
+
+    case '/theatres/7/skip_vote':
+      return Promise.resolve (buildTheatreInfo ({
+        postId:        currentPost.id,
+        postStartedAt: '2026-01-02T03:04:05.000Z',
+        postElapsedMs: 2_000,
+        watchingUsers: [{ id: 1, name: 'tester' }],
+        skipVote:      {
+          votesCount:         1,
+          requiredCount:      2,
+          watchingUsersCount: 1,
+          voted:              true,
+        },
+      }))
+
+    default:
+      return Promise.reject (new Error (`Unexpected PUT ${ path }`))
+    }
+  })
+
+  api.apiDelete.mockResolvedValue (undefined)
+  api.apiPatch.mockResolvedValue (undefined)
+  api.apiPost.mockResolvedValue (undefined)
+  postsApi.fetchPost.mockResolvedValue (currentPost)
+  dialogue.confirm.mockResolvedValue (true)
+}
+
+describe ('TheatreDetailPage', () => {
+  beforeEach (() => {
+    vi.clearAllMocks ()
+    mockDefaultApi ()
+  })
+
+  it ('loads theatre state, comments, current post, programme history, and weights', async () => {
+    renderPage ()
+
+    expect (await screen.findByText ('上映会場『上映室』')).toBeInTheDocument ()
+    expect (await screen.findByText ('Embed:上映中の投稿')).toBeInTheDocument ()
+    expect (screen.getAllByText ('視聴コメント')[0]).toBeInTheDocument ()
+    expect (screen.getAllByText ('上映中の投稿')[0]).toBeInTheDocument ()
+    expect (screen.getByText ('penalty 2')).toBeInTheDocument ()
+
+    await waitFor (() => {
+      expect (postsApi.fetchPost).toHaveBeenCalledWith ('10')
+    })
+  })
+
+  it ('votes to skip the current post', async () => {
+    renderPage ()
+
+    await screen.findByText ('Embed:上映中の投稿')
+
+    fireEvent.click (screen.getByRole ('button', { name: 'スキップ 0 / 2' }))
+
+    await waitFor (() => {
+      expect (api.apiPut).toHaveBeenCalledWith (
+          '/theatres/7/skip_vote',
+          { post_id: 10 },
+      )
+    })
+    expect (await screen.findByRole ('button', { name: 'スキップ取消 1 / 2' }))
+      .toBeInTheDocument ()
+  })
+
+  it ('deletes an owned comment after confirmation', async () => {
+    renderPage ()
+
+    fireEvent.click ((await screen.findAllByLabelText ('コメントを削除'))[0])
+
+    await waitFor (() => {
+      expect (dialogue.confirm).toHaveBeenCalled ()
+    })
+    await waitFor (() => {
+      expect (api.apiDelete).toHaveBeenCalledWith ('/theatres/7/comments/2')
+    })
+    expect (await screen.findAllByText ('削除されました．')).toHaveLength (2)
+  })
+})
diff --git a/frontend/src/test/factories.ts b/frontend/src/test/factories.ts
index 2092619..94a09ed 100644
--- a/frontend/src/test/factories.ts
+++ b/frontend/src/test/factories.ts
@@ -1,4 +1,13 @@
-import type { Material, Post, Tag, User, WikiPage } from '@/types'
+import type { Material,
+	      Post,
+	      Tag,
+	      Theatre,
+	      TheatreComment,
+	      TheatreInfo,
+	      TheatrePostSelectionWeights,
+	      TheatreProgramme,
+	      User,
+	      WikiPage } from '@/types'
 
 export const buildTag = (overrides: Partial<Tag> = {}): Tag => ({
   id:             1,
@@ -72,3 +81,62 @@ export const buildMaterial = (overrides: Partial<Material> = {}): Material => ({
   updatedByUser: { id: 2, name: 'updater' },
   ...overrides,
 })
+
+export const buildTheatre = (overrides: Partial<Theatre> = {}): Theatre => ({
+  id:            1,
+  name:          'テスト劇場',
+  opensAt:       '2026-01-02T03:04:05.000Z',
+  closesAt:      null,
+  createdByUser: { id: 1, name: 'creator' },
+  createdAt:     '2026-01-02T03:04:05.000Z',
+  updatedAt:     '2026-01-03T03:04:05.000Z',
+  ...overrides,
+})
+
+export const buildTheatreInfo = (
+    overrides: Partial<TheatreInfo> = {},
+): TheatreInfo => ({
+  hostFlg:       false,
+  postId:        null,
+  postStartedAt: null,
+  postElapsedMs: null,
+  watchingUsers: [],
+  skipVote:      {
+    votesCount:         0,
+    requiredCount:      1,
+    watchingUsersCount: 0,
+    voted:              false,
+  },
+  ...overrides,
+})
+
+export const buildTheatreComment = (
+    overrides: Partial<TheatreComment> = {},
+): TheatreComment => ({
+  theatreId: 1,
+  no:        1,
+  deleted:   false,
+  user:      { id: 1, name: 'tester' },
+  content:   'テストコメント',
+  createdAt: '2026-01-02T03:04:05.000Z',
+  ...overrides,
+} as TheatreComment)
+
+export const buildTheatreProgramme = (
+    overrides: Partial<TheatreProgramme> = {},
+): TheatreProgramme => ({
+  theatreId: 1,
+  position:  1,
+  post:      buildPost (),
+  createdAt: '2026-01-02T03:04:05.000Z',
+  ...overrides,
+})
+
+export const buildTheatrePostSelectionWeights = (
+    overrides: Partial<TheatrePostSelectionWeights> = {},
+): TheatrePostSelectionWeights => ({
+  tagPenalties:  [],
+  lightestPosts: [],
+  heaviestPosts: [],
+  ...overrides,
+})