[Tsuwabuki]

Wow.

Just... Wow.

I've read this entire thread. Carefully. I will reiterate what I am sure has been said in pretty clear terms:

If you want to live in Japan:

DO graduate from high school.
DO graduate from college.
DO study the language as early as possible.
DO study up on the culture and history.
DO a home stay, semester abroad, or vacation if you can.
DO apply for many jobs in many places.
DO read over your contract and applicable parts of the MOI, MOJ, and MOL websites/documentation.
DO ask lots and lots of questions.
DO provide the maximum number of documents, not the minimum.

DON'T think killyoself's one in a million chance applies to you. It might, but then playing russian roulette with five bullets in a six shot revolver might leave you alive too.
DON'T think everyone will accommodate your cultural values (or just accommodate YOU any more than anyone else)
DON'T think you can survive successfully without learning Japanese.
DON'T think you can lie, fudge, or omit with immigration.
DON'T think you deserve a job because you're [insert here] (white, rich, smart, American, related to the the Windsors, are from Mars).
DON'T trust your employer to do everything for you.
DON'T just take my word for it, or anyone else's. You are responsible for yourself and your career. As Reagan said, trust but verify.

I say this because me? I am not lucky. When I don't do things By The Book, They Throw the Book at Me. Thus, I am not a risky person by nature. If you take risks and screw up, don't whine to anyone else.

YOU ARE THE ONLY ONE LOOKING OUT FOR YOU.

As for the teaching angle, I went to school to teach. I love teaching. I would love it in America too. But Japan is more fitted to my lifestyle. However, the interest in teaching came first. I would recommend, although do not insist, that people learn to teach or learn they love teaching prior to coming here, but just don't stay here if you don't. I've seen too many people, as Nyororin has said, that are just here for the beer and the women and their own little world. They forget that the kids they teach are the reason they have a job at the least, and at the most are the next generation of an increasingly global citizenry who deserve the best education they can get regardless of their country, or the country of origin their instructors. If the kids aren't your main reason for being here, then after you do your year, please just go.