In Germany, you can rewrite from a Japanese license to a German license after six months have passed. (Umschreibung)
For rewriting, you need to go to the LBV transportation department.
Unlike visa application etc. here, we can make a reservation online, so there was not much trouble.
Those you bring are passport, resident card (Meldebescheinigung), photograph (same as for visa), Japanese license, Japanese license (translated by Japanese Consulate)
At the time of the procedure you will be asked if you need a temporary license that you can use until your driver’s license arrives, but those who are not needed immediately are unnecessary.
Also, the Japanese driver ‘s license was returned on the spot, there was a pattern of returning it by mail postage and returned via the Japanese consular office.
I was returned via consular office and my wife from LBV by post. I do not quite understand the difference …