[jasonbvr]

Your absolute best course of action:

1. Get into the best US university that you can. I can't emphasize the US part enough. In a worldwide survey of schools, the US still leads globally in university education. Do a semester or two abroad and don't simply stick to Japan. Pick China or somewhere in Europe.
2. For your major you will either want something like global finance/business, mechanical or structural engineering, or programming/networking.
3. Go for the best internship you can and graduate with all the honors you can achieve.
4. Get a job here doing something like engineering. If you do it right, you will be making 60,000 USD a year or more right out of school.

If none of the above sounds appealing, do your four years studying whatever and teach English.