You should have a degree to get a teaching job, but YEARS of experience and no degree can get you some jobs including teaching.
Japanese is NOT required for 99% of English teaching jobs (many schools ban their teachers from speaking Japanese!) but Japanese is required for many other jobs.. it all depends...

When getting information about Japan, try to get it from folks who are actually in Japan and have been here for a long time.. there are a lot of folks who came here once for a week or a year and think they know it all... but often they don't