diff --git a/backend/db/migrate/20260922030000_add_columns_to_tag_names.rb b/backend/db/migrate/20260922030000_add_columns_to_tag_names.rb
index 083a414..6f203ca 100644
--- a/backend/db/migrate/20260922030000_add_columns_to_tag_names.rb
+++ b/backend/db/migrate/20260922030000_add_columns_to_tag_names.rb
@@ -7,6 +7,8 @@ class AddColumnsToTagNames < ActiveRecord::Migration[8.0]
                null: false, after: :name, default: 'Jpan'
     add_column :tag_names, :primary_flg, :boolean,
                null: false, after: :script_code, default: true
+    add_column :tag_names, :auto_generated, :boolean,
+               null: false, default: true, after: :primary_flg
 
     add_foreign_key :tag_names, :languages, column: :language_code, primary_key: :code
     add_foreign_key :tag_names, :scripts, column: :script_code, primary_key: :code
@@ -51,6 +53,7 @@ class AddColumnsToTagNames < ActiveRecord::Migration[8.0]
     remove_index :tag_names, [:language_code, :name]
     add_index :tag_names, :name, unique: true
 
+    remove_column :tag_names, :auto_generated
     remove_column :tag_names, :primary_flg
     remove_column :tag_names, :script_code
     remove_column :tag_names, :language_code
diff --git a/backend/db/migrate/20260922040000_add_names_to_tag_versions.rb b/backend/db/migrate/20260922040000_add_names_to_tag_versions.rb
index c64f9eb..af7e5a7 100644
--- a/backend/db/migrate/20260922040000_add_names_to_tag_versions.rb
+++ b/backend/db/migrate/20260922040000_add_names_to_tag_versions.rb
@@ -9,23 +9,17 @@ class AddNamesToTagVersions < ActiveRecord::Migration[8.0]
 
     say_with_time 'Backfilling multilingual tag version names' do
       TagVersion.find_each do |version|
-        names = [{
-          language_code: 'ja',
-          name: version.name,
-          script_code: 'Jpan',
-          primary_flg: true,
-          auto_generated: false }]
-        names.concat(version.aliases.to_s.split.filter_map { |name|
-          next if name.blank?
-
-          {
-            language_code: 'ja',
-            name:,
-            script_code: 'Jpan',
-            primary_flg: false,
-            auto_generated: false }
-        })
-        version.update_columns(names: names)
+        aliases = version.aliases.to_s.split.filter_map do |name|
+          name.present? &&
+              { name:,
+                script_code: 'Jpan',
+                auto_generated: false }
+        end
+        names = { ja: { name: version.name,
+                        script_code: 'Jpan',
+                        auto_generated: false,
+                        aliases: } }
+        version.update_columns(names:)
       end
     end
 
diff --git a/backend/db/migrate/20260922050000_add_auto_generated_to_tag_names.rb b/backend/db/migrate/20260922050000_add_auto_generated_to_tag_names.rb
deleted file mode 100644
index 79cb3cc..0000000
--- a/backend/db/migrate/20260922050000_add_auto_generated_to_tag_names.rb
+++ /dev/null
@@ -1,19 +0,0 @@
-class AddAutoGeneratedToTagNames < ActiveRecord::Migration[8.0]
-  class TagVersion < ActiveRecord::Base
-    self.table_name = 'tag_versions'
-  end
-
-  def up
-    add_column :tag_names, :auto_generated, :boolean, null: false, default: false
-    TagVersion.reset_column_information
-
-    TagVersion.find_each do |version|
-      names = Array(version.names).map { |name| name.merge('auto_generated' => false) }
-      version.update_columns(names: names)
-    end
-  end
-
-  def down
-    remove_column :tag_names, :auto_generated
-  end
-end
diff --git a/backend/db/schema.rb b/backend/db/schema.rb
index bab1a8e..238aac4 100644
--- a/backend/db/schema.rb
+++ b/backend/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[8.0].define(version: 2026_09_22_050000) do
+ActiveRecord::Schema[8.0].define(version: 2026_09_22_040000) do
   create_table "active_storage_attachments", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
     t.string "name", null: false
     t.string "record_type", null: false
@@ -450,11 +450,11 @@ ActiveRecord::Schema[8.0].define(version: 2026_09_22_050000) do
     t.string "name", null: false
     t.string "script_code", limit: 4, null: false
     t.boolean "primary_flg", null: false
+    t.boolean "auto_generated", default: true, null: false
     t.bigint "canonical_id"
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
     t.virtual "primary_tag_id", type: :bigint, as: "(case when `primary_flg` then `tag_id` else NULL end)"
-    t.boolean "auto_generated", default: false, null: false
     t.index ["canonical_id"], name: "index_tag_names_on_canonical_id"
     t.index ["language_code", "name"], name: "index_tag_names_on_language_code_and_name", unique: true
     t.index ["primary_tag_id", "language_code"], name: "index_tag_names_on_primary_tag_id_and_language_code", unique: true