* 🌐 Add Japanese translation for `docs/ja/docs/python-types.md`. PR [#1899](https://github.com/tiangolo/fastapi/pull/1899) by [@SwftAlpc](https://github.com/SwftAlpc).
* 🌐 Add Japanese translation for `docs/ja/docs/tutorial/handling-errors.md`. PR [#1953](https://github.com/tiangolo/fastapi/pull/1953) by [@SwftAlpc](https://github.com/SwftAlpc).
* 🌐 Add Japanese translation for `docs/ja/docs/tutorial/response-status-code.md`. PR [#1942](https://github.com/tiangolo/fastapi/pull/1942) by [@SwftAlpc](https://github.com/SwftAlpc).
* 🌐 Add Japanese translation for `docs/ja/docs/tutorial/extra-models.md`. PR [#1941](https://github.com/tiangolo/fastapi/pull/1941) by [@SwftAlpc](https://github.com/SwftAlpc).