Travel, Teach, Live in Japan
Good God. What planet are you living on?
I've taught in five different countries, including 2 years in Japan. I've been teaching for 13 years. Believe me (or not), teaching English in Japan is the least rewarding experience I've had in teaching (though I loved the Japanese themselves). I suppose the main reason why there are so many unqualified (and I'm not talking about university - as you should know) and inexperienced teachers in the Far East is that it's the only place nowadays that unqualified teachers can actually get work.
Another reason is the very low learning expectations of Japanese students studying English.
Most teaching in Japan is actually not teaching. Most teachers there are just going through motions without any idea why they're doing what they're doing.
Qualifications are there for a reason. I'd hate to see a dentist who had no qualifications. There are so many areas where I'd demand to be seen by a qualified person. Likewise I'd never pay for lessons from someone who had no idea of teaching - theory or practice.
I worry that you think it's easy to wing teaching. It speaks volumes about the kind of teaching you've been exposed to - and I wouldn't actually call it teaching.