Firefoxのビルトイン翻訳の日本語対応、2024年後半から取り組む予定らしい・・・＞＜
https://connect.mozilla.org/t5/ideas/japanese-translate-option-in-firefox-translations/idi-p/22959/page/2#comments
"We are planning to start working on Japanese in the second half of 2024."