where to live in japan

I am a student thinking of joining a Japanese teaching assistant job and i can state where i would like to be placed. Does anyone know the best prefectures to live? Not in a big city like tokyo but not to small.

try Kyoto.

you might try doing a little research on climates in japan. They really vary from Hokkaido down to Okinawa, and even on the island of Honshu...for example, I live near Yokohama and rarely if ever see it snow here. But in Nagano or Niigata, not that far away, there is ample snow and mountain scenery.
Then again if you want near tropics, try Okinawa. I think Nagasaki, Hiroshima Aomori and Sapporo look like nice livable places but then, I've never lived there.
Tokyo is such a transportation hub for shinkansen and international flights, not to mention a place where you can find a lot of international resources.
Is the prefecture all you get to choose? Because even then, prefectures are pretty large.

Yes i think the form says name 3 or 4 prefectures is all. I was looking at the chubu area. Its between kanto and kansai and not too south or north. Do you know anything about nagoya and is yokohama nice?

Well you do really have a lot to consider. There are quite a few nice places. Hiroshima is not too bad, it has a lot to offer and is in a decent location. If you want to try some place where you will not see as many foreigners you should check out Matsuyama in Ehime Prefecture. Very nice place, actually quite a bit to do. Transportation is pretty well set up down town. With overnight buses to many places (even up to Tokyo). Yokohama is pretty much an outskirt of Tokyo lol if you want to put it like that. Otherwise Kyoto would be a nice place, very touristy though.