I believe he mentioned in another post he wants to live there at 18...
I don't think you'll have much luck without going to a university first. Try this page for more information -
Japanese Visa Information :: Japan Visitor
I know it's a lot of information, so I'll sum it up for you: to live in Japan, you need a visa. You either need to have a bachelor's degree from a university (typically 4 year course of study), or you need to be a student in Japan. Trust me, if you don't know Japanese, going to a university in the US is much easier and more economical... even if you have to wait 4 years.