[Sangetsu]

You would have more luck finding a foreigner in Japan who needs a roommate than you would finding a host family. I wouldn't mind a roommate as it would be nice to have someone to speak English with from time to time, but I am always busy and am often away from home. Besides that, my current apartment is typically Tokyo-tiny, and I won't be able to move into larger place until next year.

If you look around you should be able to find someone willing to take you in for awhile.