JAF translation service is a bit of a performance - Application should be submitted when you are in Japan. Turnaround time is 2 weeks. Cannot handle licenses that have handwritten comments ... etc. but if you have a friend in Japan or a VPN you can probably jump through all of the hoops before you get here.

On a positive note, you can submit your license online and print it at a 7-Eleven (within a limited window of time). Furthermore, the translation is valid for as long as your license is valid, so once you get it you're set for future trips to Japan.

https://english.jaf.or.jp/driving-in...an/about-dltas