What certifications have you gotten in Japan?

So recently I learned there was a license I needed to operate a simple Chainsaw. There are also very intense and multi-year certifications for relatively unique jobs like 行政書士 (administrative scrivener) which is halfway between a paralegal and a lawyer.

What certifications have you gotten in Japan? How long did it take? And what did you use to study?

I just got PR and I want to open more doors, so I wanted to ask what people have done. Since japanlife has been a lot of doom scrolling lately I wanted to know what people actually accomplished and what it enables to them to do and if they found work with it or not.

by ExPatriot0