diff --git a/frontend/messages/ja.json b/frontend/messages/ja.json
index 9f293dab..c22e01f5 100644
--- a/frontend/messages/ja.json
+++ b/frontend/messages/ja.json
@@ -202,6 +202,14 @@
 	"this_can_be_useful_for_selfsigned_certificates": "これは自己署名証明書の場合に有用です。",
 	"enabled_emails": "有効なメール",
 	"email_login_notification": "メールログイン通知",
+	"email_login_notification_description": "Choose when users receive an email after signing in.",
+	"login_notification_disabled_description": "Do not send sign-in notification emails or use browser recognition cookies.",
+	"login_notification_always": "Every sign-in",
+	"login_notification_always_description": "Send an email after every successful sign-in. No browser recognition cookie is used.",
+	"login_notification_ip_and_user_agent": "New IP address or browser",
+	"login_notification_ip_and_user_agent_description": "Send an email when the exact combination of IP address and browser User-Agent is not in the user's sign-in history. No browser recognition cookie is used.",
+	"login_notification_browser_recognition": "Unrecognized browser",
+	"login_notification_browser_recognition_description": "Send an email unless the browser is recognized by its cookie or a matching IP address and User-Agent in the user's sign-in history.",
 	"send_an_email_to_the_user_when_they_log_in_from_a_new_device": "ユーザーが新しいデバイスからログインした際にメールを送信する。",
 	"emai_login_code_requested_by_user": "ユーザーがリクエストしたメールログインコード",
 	"allow_users_to_sign_in_with_a_login_code_sent_to_their_email": "ユーザーがメールに送信されたログインコードをリクエストすることでパスキーをバイパスできるようにします。これによりセキュリティが大幅に低下し、ユーザーのメールにアクセスできる者なら誰でもログイン可能になります。",