diff --git a/po/ja.po b/po/ja.po
index e853436c..53a4a38c 100644
--- a/po/ja.po
+++ b/po/ja.po
@@ -3,7 +3,7 @@ msgstr ""
 "Project-Id-Version: clapper\n"
 "Report-Msgid-Bugs-To: \n"
 "POT-Creation-Date: 2021-09-14 16:35+0200\n"
-"PO-Revision-Date: 2021-09-14 15:25\n"
+"PO-Revision-Date: 2022-03-31 08:08\n"
 "Last-Translator: \n"
 "Language-Team: Japanese\n"
 "Language: ja_JP\n"
@@ -19,441 +19,441 @@ msgstr ""
 
 #: ui/clapper.ui:6
 msgid "Open Files…"
-msgstr ""
+msgstr "ファイルを開く…"
 
 #: ui/clapper.ui:10
 msgid "Open URI…"
-msgstr ""
+msgstr "URIを開く..."
 
 #: ui/clapper.ui:16 ui/preferences-window.ui:4
 msgid "Preferences"
-msgstr ""
+msgstr "設定"
 
 #: ui/clapper.ui:20
 msgid "Shortcuts"
-msgstr ""
+msgstr "ショートカット"
 
 #: ui/clapper.ui:26
 msgid "About Clapper"
-msgstr ""
+msgstr "Clapperについて"
 
 #: ui/elapsed-time-button.ui:27
 msgid "Speed"
-msgstr ""
+msgstr "速度"
 
 #: ui/elapsed-time-button.ui:41 ui/preferences-window.ui:83
 #: ui/preferences-window.ui:215
 msgid "Normal"
-msgstr ""
+msgstr "標準"
 
 #: ui/help-overlay.ui:10 ui/preferences-window.ui:12
 msgid "General"
-msgstr ""
+msgstr "一般"
 
 #: ui/help-overlay.ui:13
 msgid "Show shortcuts"
-msgstr ""
+msgstr "ショートカットを表示する"
 
 #: ui/help-overlay.ui:19
 msgid "Toggle fullscreen"
-msgstr ""
+msgstr "フルスクリーン切り替え"
 
 #: ui/help-overlay.ui:20
 msgid "Double tap | Double click"
-msgstr ""
+msgstr "ダブルタップ | ダブルクリック"
 
 #: ui/help-overlay.ui:26
 msgid "Leave fullscreen"
-msgstr ""
+msgstr "フルスクリーンを終了"
 
 #: ui/help-overlay.ui:32
 msgid "Reveal OSD (fullscreen only)"
-msgstr ""
+msgstr "OSDを表示 (全画面表示の場合のみ)"
 
 #: ui/help-overlay.ui:33
 msgid "Tap"
-msgstr ""
+msgstr "タップ"
 
 #: ui/help-overlay.ui:39
 msgid "Quit"
-msgstr ""
+msgstr "終了"
 
 #: ui/help-overlay.ui:47
 msgid "Media"
-msgstr ""
+msgstr "メディア"
 
 #: ui/help-overlay.ui:50
 msgid "Open files"
-msgstr ""
+msgstr "ファイルを開く"
 
 #: ui/help-overlay.ui:56 src/dialogs.js:137
 msgid "Open URI"
-msgstr ""
+msgstr "URIを開く"
 
 #: ui/help-overlay.ui:64
 msgid "Playlist"
-msgstr ""
+msgstr "プレイリスト"
 
 #: ui/help-overlay.ui:67
 msgid "Next item"
-msgstr ""
+msgstr "次の項目"
 
 #: ui/help-overlay.ui:68
 msgid "Double tap (right side)"
-msgstr ""
+msgstr "ダブルタップ（右端）"
 
 #: ui/help-overlay.ui:74
 msgid "Previous item"
-msgstr ""
+msgstr "前の項目"
 
 #: ui/help-overlay.ui:75
 msgid "Double tap (left side)"
-msgstr ""
+msgstr "ダブルタップ（左端）"
 
 #: ui/help-overlay.ui:81
 msgid "Change repeat mode"
-msgstr ""
+msgstr "リピートモードを変更"
 
 #: ui/help-overlay.ui:87
 msgid "Export to file"
-msgstr ""
+msgstr "ファイルへエクスポート"
 
 #: ui/help-overlay.ui:95 ui/preferences-window.ui:119
 msgid "Playback"
-msgstr ""
+msgstr "プレイバック"
 
 #: ui/help-overlay.ui:98
 msgid "Toggle play"
-msgstr ""
+msgstr "一時停止・再生"
 
 #: ui/help-overlay.ui:99
 msgid "Long press | Right click"
-msgstr ""
+msgstr "Long press | Right click"
 
 #: ui/help-overlay.ui:105
 msgid "Seek forward"
-msgstr ""
+msgstr "早送り"
 
 #: ui/help-overlay.ui:106
 msgid "Swipe right | Scroll right"
-msgstr ""
+msgstr "右スワイプ | 右スクロール"
 
 #: ui/help-overlay.ui:112
 msgid "Seek backward"
-msgstr ""
+msgstr "巻き戻し"
 
 #: ui/help-overlay.ui:113
 msgid "Swipe left | Scroll left"
-msgstr ""
+msgstr "左スワイプ | 左スクロール"
 
 #: ui/help-overlay.ui:119
 msgid "Volume up"
-msgstr ""
+msgstr "音量を上げる"
 
 #: ui/help-overlay.ui:120
 msgid "Swipe up | Scroll up"
-msgstr ""
+msgstr "上スワイプ | 上スクロール"
 
 #: ui/help-overlay.ui:126
 msgid "Volume down"
-msgstr ""
+msgstr "音量を下げる"
 
 #: ui/help-overlay.ui:127
 msgid "Swipe down | Scroll down"
-msgstr ""
+msgstr "下スワイプ  |  下スクロール"
 
 #: ui/help-overlay.ui:133
 msgid "Toggle mute"
-msgstr ""
+msgstr "ミュート切り替え"
 
 #: ui/help-overlay.ui:139
 msgid "Next chapter"
-msgstr ""
+msgstr "次のチャプターへ"
 
 #: ui/help-overlay.ui:145
 msgid "Previous chapter"
-msgstr ""
+msgstr "前のチャプターへ\""
 
 #: ui/preferences-plugin-ranking-subpage.ui:11
 msgid "Decoders"
-msgstr ""
+msgstr "デコーダー"
 
 #: ui/preferences-plugin-ranking-subpage.ui:18
 msgid "Return to the preferences"
-msgstr ""
+msgstr "設定へ戻る"
 
 #: ui/preferences-window.ui:16
 msgid "Behavior"
-msgstr ""
+msgstr "挙動"
 
 #: ui/preferences-window.ui:19
 msgid "Auto fullscreen"
-msgstr ""
+msgstr "自動的にフルスクリーンに切り替える"
 
 #: ui/preferences-window.ui:20
 msgid "Enter fullscreen when playlist is replaced except floating mode"
-msgstr ""
+msgstr "フローティングモードを除き、プレイリストを入れ替えた場合に自動的にフルスクリーンにする"
 
 #: ui/preferences-window.ui:26
 msgid "Ask to resume recent media"
-msgstr ""
+msgstr "前回再生したメディアを続きから再生するか尋ねる"
 
 #: ui/preferences-window.ui:32
 msgid "Float on all workspaces"
-msgstr ""
+msgstr "すべてのワークスペースにフロートを配置する"
 
 #: ui/preferences-window.ui:33
 msgid "This option only works on GNOME"
-msgstr ""
+msgstr "このオプションはGnomeでのみ機能します"
 
 #: ui/preferences-window.ui:39
 msgid "After playback"
-msgstr ""
+msgstr "再生終了後"
 
 #: ui/preferences-window.ui:44
 msgid "Do nothing"
-msgstr ""
+msgstr "何もしない"
 
 #: ui/preferences-window.ui:45
 msgid "Freeze last frame"
-msgstr ""
+msgstr "最後のフレームで停止する"
 
 #: ui/preferences-window.ui:46
 msgid "Close the app"
-msgstr ""
+msgstr "アプリを閉じる"
 
 #: ui/preferences-window.ui:56
 msgid "Volume"
-msgstr ""
+msgstr "音量"
 
 #: ui/preferences-window.ui:59
 msgid "Custom initial value"
-msgstr ""
+msgstr "初期音量を設定する"
 
 #: ui/preferences-window.ui:60
 msgid "Set custom volume at startup instead of restoring it"
-msgstr ""
+msgstr "前回使用した音量を使用するのではなく、起動時に音量をカスタム値に設定します"
 
 #: ui/preferences-window.ui:64
 msgid "Volume percentage"
-msgstr ""
+msgstr "音量（％）"
 
 #: ui/preferences-window.ui:75
 msgid "Seeking"
-msgstr ""
+msgstr "シーキング"
 
 #: ui/preferences-window.ui:78
 msgid "Mode"
-msgstr ""
+msgstr "モード"
 
 #: ui/preferences-window.ui:84
 msgid "Accurate"
-msgstr ""
+msgstr "精密"
 
 #: ui/preferences-window.ui:85
 msgid "Fast"
-msgstr ""
+msgstr "高速"
 
 #: ui/preferences-window.ui:93
 msgid "Unit"
-msgstr ""
+msgstr "ユニット"
 
 #: ui/preferences-window.ui:98
 msgid "Second"
-msgstr ""
+msgstr "秒"
 
 #: ui/preferences-window.ui:99
 msgid "Minute"
-msgstr ""
+msgstr "分"
 
 #: ui/preferences-window.ui:100
 msgid "Percentage"
-msgstr ""
+msgstr "パーセント"
 
 #: ui/preferences-window.ui:108
 msgid "Value"
-msgstr ""
+msgstr "値"
 
 #: ui/preferences-window.ui:123
 msgid "Audio"
-msgstr ""
+msgstr "オ−ディオ"
 
 #: ui/preferences-window.ui:126
 msgid "Offset in milliseconds"
-msgstr ""
+msgstr "オフセット（ミリ秒）"
 
 #: ui/preferences-window.ui:133
 msgid "Only native audio formats"
-msgstr ""
+msgstr "ネイティブオーディオフォーマットのみを使用する"
 
 #: ui/preferences-window.ui:141
 msgid "Subtitles"
-msgstr ""
+msgstr "字幕"
 
 #: ui/preferences-window.ui:144
 msgid "Default font"
-msgstr ""
+msgstr "既定のフォント"
 
 #: ui/preferences-window.ui:154
 msgid "Network"
-msgstr ""
+msgstr "ネットワーク"
 
 #: ui/preferences-window.ui:158
 msgid "Client"
-msgstr ""
+msgstr "クライアント"
 
 #: ui/preferences-window.ui:161
 msgid "Progressive download buffering"
-msgstr ""
+msgstr "プログレッシブなバッファリングを使用する"
 
 #: ui/preferences-window.ui:169
 msgid "Server"
-msgstr ""
+msgstr "サーバー"
 
 #: ui/preferences-window.ui:172
 msgid "Control player remotely"
-msgstr ""
+msgstr "プレーヤーをリモートでコントロールする"
 
 #: ui/preferences-window.ui:176
 msgid "Listening port"
-msgstr ""
+msgstr "待ち受けポート"
 
 #: ui/preferences-window.ui:183
 msgid "Run web application in background"
-msgstr ""
+msgstr "Webアプリケーションをバックグラウンドで実行する"
 
 #: ui/preferences-window.ui:184
 msgid "Requires GTK compiled with Broadway backend"
-msgstr ""
+msgstr "Broadwayバックエンドでコンパイルされた GTK が必要です"
 
 #: ui/preferences-window.ui:190
 msgid "Web application port"
-msgstr ""
+msgstr "Webアプリケーションのポート"
 
 #: ui/preferences-window.ui:204
 msgid "Prefer adaptive streaming"
-msgstr ""
+msgstr "アダプティブストリーミングを優先する"
 
 #: ui/preferences-window.ui:210
 msgid "Max quality"
-msgstr ""
+msgstr "Max quality"
 
 #: ui/preferences-window.ui:228
 msgid "Tweaks"
-msgstr ""
+msgstr "詳細設定"
 
 #: ui/preferences-window.ui:232
 msgid "Appearance"
-msgstr ""
+msgstr "外観"
 
 #: ui/preferences-window.ui:235
 msgid "Dark theme"
-msgstr ""
+msgstr "ダークテーマ"
 
 #: ui/preferences-window.ui:241
 msgid "Render window shadows"
-msgstr ""
+msgstr "ウィンドウの影をレンダリングする"
 
 #: ui/preferences-window.ui:242
 msgid "Disable to increase performance when windowed"
-msgstr ""
+msgstr "無効化するとウィンドウモードでのパフォーマンスが向上します"
 
 #: ui/preferences-window.ui:253
 msgid "Plugin ranking"
-msgstr ""
+msgstr "プライグインの優先順位"
 
 #: ui/preferences-window.ui:254
 msgid "Alter default ranks of GStreamer plugins"
-msgstr ""
+msgstr "GStreamerプラグインの優先順位を変更します"
 
 #: ui/preferences-window.ui:259
 msgid "Use playbin3"
-msgstr ""
+msgstr "playbin3を使用"
 
 #: ui/preferences-window.ui:260 ui/preferences-window.ui:269
 msgid "Requires player restart"
-msgstr ""
+msgstr "プレイヤーの再起動が必要です"
 
 #: ui/preferences-window.ui:262 ui/preferences-window.ui:271
 msgid "Experimental"
-msgstr ""
+msgstr "試験運用機能"
 
 #: ui/preferences-window.ui:268
 msgid "Use PipeWire for audio output"
-msgstr ""
+msgstr "オーディオ出力にPipeWireを使用する"
 
 #: src/buttons.js:201
 #, javascript-format
 msgid "Decoder: %s"
-msgstr ""
+msgstr "デコーダー: %s"
 
 #: src/dialogs.js:152
 msgid "Enter or drop URI here"
-msgstr ""
+msgstr "ここにURIを入力またはドロップ"
 
 #: src/dialogs.js:157
 msgid "Cancel"
-msgstr ""
+msgstr "キャンセル"
 
 #: src/dialogs.js:158
 msgid "Open"
-msgstr ""
+msgstr "開く"
 
 #: src/dialogs.js:226
 msgid "Title"
-msgstr ""
+msgstr "タイトル"
 
 #: src/dialogs.js:227
 msgid "Completed"
-msgstr ""
+msgstr "再生済み"
 
 #: src/dialogs.js:235
 msgid "Resume playback?"
-msgstr ""
+msgstr "前回の続きから再生しますか？"
 
 #: src/dialogs.js:289
 #, javascript-format
 msgid "GTK version: %s"
-msgstr ""
+msgstr "GTKバージョン: %s"
 
 #: src/dialogs.js:290
 #, javascript-format
 msgid "Adwaita version: %s"
-msgstr ""
+msgstr "Adwaitaバージョン: %s"
 
 #: src/dialogs.js:291
 #, javascript-format
 msgid "GStreamer version: %s"
-msgstr ""
+msgstr "GStreamer バージョン: %s"
 
 #: src/dialogs.js:292
 #, javascript-format
 msgid "GJS version: %s"
-msgstr ""
+msgstr "GJS バージョン: %s"
 
 #: src/dialogs.js:300
 msgid "A GNOME media player powered by GStreamer"
-msgstr ""
+msgstr "GStreamerを使用したGNOME向けのメディアプレーヤー"
 
 #. TRANSLATORS: Put your name(s) here for credits or leave untranslated
 #: src/dialogs.js:305
 msgid "translator-credits"
-msgstr ""
+msgstr "翻訳者"
 
 #: src/revealers.js:170
 #, javascript-format
 msgid "Ends at: %s"
-msgstr ""
+msgstr "再生終了時刻: %s"
 
 #: src/widget.js:227 src/widget.js:236 src/widget.js:242 src/widget.js:248
 msgid "Undetermined"
-msgstr ""
+msgstr "不明"
 
 #: src/widget.js:243
 msgid "Channels"
-msgstr ""
+msgstr "チャンネル"
 
 #: src/widget.js:261
 msgid "Disabled"
-msgstr ""
+msgstr "Disabled"