* 🌐 Add Japanese translation for Tutorial - Testing. PR [#2259](https://github.com/tiangolo/fastapi/pull/2259) by [@tokusumi](https://github.com/tokusumi).
* 🌐 Add Japanese translation for Tutorial - Debugging. PR [#2256](https://github.com/tiangolo/fastapi/pull/2256) by [@tokusumi](https://github.com/tokusumi).
* 🌐 Add Japanese translation for Tutorial - Middleware. PR [#2255](https://github.com/tiangolo/fastapi/pull/2255) by [@tokusumi](https://github.com/tokusumi).
* 🌐 Add Japanese translation for Concurrency and async / await. PR [#2058](https://github.com/tiangolo/fastapi/pull/2058) by [@tokusumi](https://github.com/tokusumi).