There are three ways which i know of that can get you to Japan (short trip).
1. Pay for a 2 week holiday in Japan, staying in hotels and joining a tour (or walk around yourself)
2. Go to school and do a student exchange program.
3. Join a program called JET. it is an american program which allows people to go to Japan and teach english. i
don't really know about this much, but maybe someone else does.
i think this is listed in order of decreasing cost, Japanese hotels are expensive because of the land value in Japan.
The student exchange program you can live with a japanese family, which is cost effective and much better than a hotel
because you get to experience the actual japanese culture. i think JET is a 2 year program, and there isn't much of
a positive feedback coming from the person doing that program, so if you think you might hate the Japanese lifestyle, i
wouldn't reccomend it.