Working Holiday with (Bio)Mathematics in Japan?

I recently finished my Master’s degree in Biomathematics and I’m seriously considering doing a Working Holiday in Japan before it's too late.

Ideally, I’d like to find some kind of work related to science, environment, data analysis while in Japan. I could also see myself teaching English or working in education-related jobs, since I’m considering becoming a teacher long-term anyway.

I’m 27 now, so I feel a bit pressured to gain some “real” work experience in my field instead of only doing casual jobs. At the same time, I don’t care too much about salary during the Working Holiday as long as it helps me get by.

My biggest concern is that I currently don’t speak Japanese. How realistic is it to manage to find something in my niche, if I don't speak the language?

I’d really appreciate advice or experiences from people who did something similar.

by Bananenschwindler