diff --git a/js/src/i18n/ja.json b/js/src/i18n/ja.json
index 7afc83fec..2e53ab859 100644
--- a/js/src/i18n/ja.json
+++ b/js/src/i18n/ja.json
@@ -82,7 +82,7 @@
   "All activities": "全てのアクティビティ",
   "All good, let's continue!": "",
   "All the places have already been taken": "すでに満員になりました",
-  "Allow all comments from users with accounts": "",
+  "Allow all comments from users with accounts": "ログインしているユーザーはコメントができる",
   "Allow registrations": "アカウント新規登録",
   "An URL to an external ticketing platform": "",
   "An error has occured while refreshing the page.": "ページを更新中にエラーが発生しました。",
@@ -121,7 +121,7 @@
   "Are you sure you want to delete this entire discussion?": "本当に全ての議論を削除しますか？",
   "Are you sure you want to delete this event? This action cannot be reverted.": "本当にこのイベントを削除しますか？取り戻すことはできません。",
   "Are you sure you want to delete this post? This action cannot be reverted.": "本当にこの投稿を削除しますか？このアクションは取り消しできません。",
-  "Are you sure you want to leave the group {groupName}? You'll loose access to this group's private content. This action cannot be undone.": "",
+  "Are you sure you want to leave the group {groupName}? You'll loose access to this group's private content. This action cannot be undone.": "本当に {groupName} から抜けますか？このグループのプライベート情報を見られなくなります。抜けたら取り戻すことができません。",
   "As the event organizer has chosen to manually validate participation requests, your participation will be really confirmed only once you receive an email stating it's being accepted.": "",
   "Ask your instance admin to {enable_feature}.": "{enable_feature}についてはインスタンス管理者にお問い合わせ下さい。",
   "Assigned to": "",
@@ -156,7 +156,7 @@
   "Cancel my participation request…": "",
   "Cancel my participation…": "",
   "Cancelled": "キャンセルされました",
-  "Cancelled: Won't happen": "",
+  "Cancelled: Won't happen": "イベント中止：キャンセル",
   "Category": "カテゴリー",
   "Change": "変更",
   "Change email": "メールアドレスを変更する",
@@ -185,7 +185,7 @@
   "Comment deleted": "コメントが削除されました。",
   "Comment text can't be empty": "コメントのテキストは空白にはできません",
   "Comments": "コメント",
-  "Comments are closed for everybody else.": "",
+  "Comments are closed for everybody else.": "他の方はコメント不可です。",
   "Confirm my participation": "",
   "Confirm my particpation": "参加希望を確認する",
   "Confirm participation": "",
@@ -282,7 +282,7 @@
   "Draft": "下書き",
   "Drafts": "下書き",
   "Due on": "",
-  "Duplicate": "",
+  "Duplicate": "イベントを複製する",
   "Edit": "編集",
   "Edit post": "投稿を編集する",
   "Edit profile {profile}": "",
@@ -427,8 +427,8 @@
   "I have an account on another Mobilizon instance.": "私は別のMobizilionインスタンスにアカウントを持っています。",
   "I have an account on {instance}.": "{instance}のアカウントを持っています。",
   "I participate": "",
-  "I want to allow people to participate without an account.": "",
-  "I want to approve every participation request": "",
+  "I want to allow people to participate without an account.": "アカウントなしで参加可能に設定する。",
+  "I want to approve every participation request": "すべての参加希望依頼を手動で許可する",
   "I've been mentionned in a comment under an event": "",
   "I've been mentionned in a group discussion": "",
   "ICS feed for events": "イベントへのICSフィード",
@@ -496,14 +496,14 @@
   "Learn more": "",
   "Learn more about Mobilizon": "Mobilizonについて詳しく知る",
   "Learn more about {instance}": "{instance}について詳しく知る",
-  "Leave": "グループを去る",
+  "Leave": "抜ける",
   "Leave event": "イベント参加を取り消す",
-  "Leave group": "グループから去る",
+  "Leave group": "グループから抜ける",
   "Leaving event \"{title}\"": "「{title}」というイベント参加を取り消しています",
   "Legal": "",
   "Let's define a few settings": "",
   "License": "ライセンス",
-  "Limited number of places": "",
+  "Limited number of places": "参加可能の人数制限あり",
   "List title": "",
   "Live": "",
   "Load more": "もっと見る",
@@ -596,7 +596,7 @@
   "No message": "メッセージはありません",
   "No moderation logs yet": "モデレーションログはまだありません",
   "No more activity to display.": "",
-  "No one is participating|One person participating|{going} people participating": "",
+  "No one is participating|One person participating|{going} people participating": "参加者０人|参加者１人|参加者 {going} 人",
   "No open reports yet": "",
   "No organized events found": "主催しているイベントは見つかりませんでした",
   "No organized events listed": "",
@@ -632,16 +632,16 @@
   "Number of places": "行う場所の数",
   "OK": "OK",
   "Old password": "古いパスワード",
-  "On {date}": "",
-  "On {date} ending at {endTime}": "",
-  "On {date} from {startTime} to {endTime}": "",
-  "On {date} starting at {startTime}": "",
+  "On {date}": "{date} に行う",
+  "On {date} ending at {endTime}": "{date} の {endTime} 時に終了",
+  "On {date} from {startTime} to {endTime}": "{date} の {startTime} 時から {endTime} 時まで",
+  "On {date} starting at {startTime}": "{date} の {startTime} 時から",
   "On {instance} and other federated instances": "",
   "Online": "オンライン",
   "Online ticketing": "",
   "Online upcoming events": "これからオンラインで行っているうイベント",
   "Only accessible through link": "",
-  "Only accessible through link (private)": "",
+  "Only accessible through link (private)": "直接リンクのみで表示可能(非公開イベント)",
   "Only accessible to members of the group": "",
   "Only alphanumeric lowercased characters and underscores are supported.": "",
   "Only group members can access discussions": "グループメンバーのみ議論に参加することができます",
@@ -674,7 +674,7 @@
   "Participants": "参加者",
   "Participate": "参加する",
   "Participate using your email address": "あなたのメールアドレスを使って参加する",
-  "Participation approval": "",
+  "Participation approval": "参加希望依頼の許可設定",
   "Participation confirmation": "参加確認",
   "Participation notifications": "",
   "Participation requested!": "参加のリクエストをしました！",
@@ -856,7 +856,7 @@
   "Tag search": "タグ検索",
   "Task lists": "タスクリスト",
   "Technical details": "技術的詳細",
-  "Tentative": "",
+  "Tentative": "未定",
   "Tentative: Will be confirmed later": "仮参加：確認待ち",
   "Terms": "利用規約",
   "Terms of service": "利用規約",
@@ -910,7 +910,7 @@
   "The member was removed from the group {group}": "グループ{group}からメンバーが除外されました",
   "The membership request from {profile} was rejected": "",
   "The only way for your group to get new members is if an admininistrator invites them.": "",
-  "The organiser has chosen to close comments.": "",
+  "The organiser has chosen to close comments.": "イベントの主催者がコメント不可に設定しています。",
   "The page you're looking for doesn't exist.": "探しているページを見つかりません。",
   "The password was successfully changed": "",
   "The post {post} was created by {profile}.": "投稿{post}は{profile}によって作成されました。",
@@ -921,14 +921,14 @@
   "The technical details of the error can help developers solve the problem more easily. Please add them to your feedback.": "",
   "The {default_privacy_policy} will be used. They will be translated in the user's language.": "",
   "The {default_terms} will be used. They will be translated in the user's language.": "",
-  "There are {participants} participants.": "",
+  "There are {participants} participants.": "{participants} 人の参加者がいます。",
   "There is no activity yet. Start doing some things to see activity appear here.": "",
   "There will be no way to recover your data.": "",
   "There's no discussions yet": "まだ議論はありません",
   "These events may interest you": "お勧めのイベント",
   "These feeds contain event data for the events for which any of your profiles is a participant or creator. You should keep these private. You can find feeds for specific profiles on each profile edition page.": "",
   "These feeds contain event data for the events for which this specific profile is a participant or creator. You should keep these private. You can find feeds for all of your profiles into your notification settings.": "",
-  "This Mobilizon instance and this event organizer allows anonymous participations, but requires validation through email confirmation.": "",
+  "This Mobilizon instance and this event organizer allows anonymous participations, but requires validation through email confirmation.": "このサーバーとこのイベントの主催者が匿名参加可に設定していますが、検証メールで確認する必要があります。",
   "This URL doesn't seem to be valid": "",
   "This URL is not supported": "このURLはサポートされていません",
   "This event has been cancelled.": "このイベントはキャンセルされました。",
@@ -997,7 +997,7 @@
   "Unknown error.": "不明なエラーが発生しました。",
   "Unknown value for the openness setting.": "",
   "Unlogged participation": "",
-  "Unsaved changes": "",
+  "Unsaved changes": "まだ保存されていない編集があります",
   "Unsubscribe to browser push notifications": "",
   "Unsuspend": "",
   "Upcoming": "",
@@ -1037,8 +1037,8 @@
   "Visibility was set to an unknown value.": "公開範囲の設定に不明な値が設定されています。",
   "Visibility was set to private.": "",
   "Visibility was set to public.": "公開範囲がパブリックに設定されました。",
-  "Visible everywhere on the web": "",
-  "Visible everywhere on the web (public)": "",
+  "Visible everywhere on the web": "全インターネットから検索で見つけられることができる",
+  "Visible everywhere on the web (public)": "全インターネットから検索で見つけられることができる( 公開)",
   "Waiting for organization team approval.": "",
   "Warning": "警告",
   "We couldn't save your participation inside this browser. Not to worry, you have successfully confirmed your participation, we just couldn't save it's status in this browser because of a technical issue.": "",
@@ -1221,7 +1221,7 @@
   "{count} km": "",
   "{count} members": "",
   "{count} members or followers": "",
-  "{count} participants": "",
+  "{count} participants": "まだ参加者いない | 参加者1人 | 参加者 {count} 人",
   "{count} requests waiting": "",
   "{folder} - Resources": "",
   "{group} activity timeline": "",