Anyone know anything about working Japan?

Graduating masters in mech eng. In Western Europe soon and planning to find a job in Japan because I love Japan.

Yes I know the wages suck, yes I know working sucks, yes I know Japs hate me idgaf. I can do N3 which I know is shit but I think I'll hit N1 after two years of living in Japan based on previous experience of learning the language quite fast during my exchange study in Japan.

I'm mostly worried if any company will even hire me. I have a lot of experience in my field already, my own (small) company in manufacturing and at least three business ideas/projects I would like to propose to the company that I could work on in my field (defence).