Becoming an English Teacher in Japan?

Question:

In September, I'll becoming a junior, which means I need to start concentrating on which careers I want to partake in. My number one choice is by far to become an English teacher in Japan, but I'm still unsure of what I need to do to get there.

First of all, which classes should I be concentrating on the most now? I know English is obviously one of them, but subjects like math and science aren't something I need to worry about, right? Secondly, what do I do after high school? Do I go onto college, university, something else? Thirdly, do you know of any programs that would allow me to teach overseas? I remember reading on a website one day that there are some Japanese high schools that pay for flights (though not a lot), and can help with living expenses. Of course, this is just a bonus. I do not actually expect to receive any help. I'm totally prepared to go to Japan with a sense of independence. And fourthly, is it absolutely necessary to know how to write and speak Japanese? I'm currently trying to learn Japanese, and I know most of the major aspects of the language (the three writing systems, sentence structure, etc.) so I'm prepared to learn how to speak it fluently.

Well, thanks so much for your help!! ^^

Answer:

You need a four year degree to teach English in Japan. So anything that has to do with English or teaching will help. But I suggest you look beyond that. More often than not, teaching English in Japan isn't a life long career. Many people get burned out after just a year or two and quit. They get homesick or tired of repeating the same things over & over day after day.
Few, if any schools will pay your airfare. Some may help with housing.
You don't need any Japanese skills to teach English. As threedayP pointed out, most schools don't want Japanese to be used in the classroom.
You'll want to get a degree that can be used for something beyond teaching English to fall back on.