Hello.
I fear you underestimate the workload involved in a translation effort. OFF, a game that is at most 5 hours long, took half a year to translate - and that translation, I did out of personal interest. I cannot justify committing to a workload like this for free.
Furthermore, if the game was only released in Japan, then somebody who is able to translate between Japanese and German would be better suited to the project. Translations of translations are bound to be inaccurate.
Thank you.