[SSJup81]

I'm sorry that I can't be of much help, but I always thought that usually those attending schools (like say one attending school in Japan for a semester) usually ended up with host families. I've neve heard of situation where someone just wanted to go over there for a while and find a family to stay with. How long did you want to stay? To teach English in Japan, you need to have some kind of a degree or more than likely be TESOL certified.

That aside, you can always check out the threads in the Living in Japan section. Maybe there's some information there that can help you, like how to teach in Japan.