I think the expression you're looking for is "loosen their
ties".
Do you have a college degree?
Do you have any marketable skills?
Do you have the type of employment record that a boss would say "Hey, this guy is worth the trouble of shipping over from America" or wherever you're from?
If you answered "No" to two or more of these things, congratulations, you're going to be a "teacher" or nothing at all. Contrary to what people might believe, you can't just fly over to Japan and hope everything will fall into place. I've actually read a post on a forum saying "My dream is to wander the Japanese countryside, doing farm work in exchange for martial arts lessons." Kids these days. Mind = blown
Ask yourself "Am I worth it to a Japanese company?"
Have you ever been to Japan?
If no, ask yourself "Why in the hell am I considering moving to a country I know little to nothing about? (Anime, Japanese friend, and internet experience do not count)
As a soldier, I can apply for a post in Japan
You can try that too!
I'll admit, from the shrines and temples, the beaches and mountains, even the cities and districts, the photos make Japan look magical. A lesser man than me might say ~moe~. I, too, once felt the tide of otaku dreaming rising inside me. Then, I got real. It's a place where people work, sleep, eat, sh*t, and go about their daily lives. Visit first. If you like it, do what needs to be done. If you love it enough, get over yourself and take a teaching position.
Or you could do like me and bring a little piece of Japan home with you *wink wink*
Protip: I'm not rude, I'm being real with you. That's so much nicer than sugar coating it, don't you think?