How expensive is housing in Japan?
Housing in Japan is actually extraordinarily affordable. Rural areas are less expensive than urban areas, but in general the cost of housing is a very small portion of what you would be paid on a salary of about 3.5 million yen (about 36,645.00 USD). Typical rent can be as low as 20,000 yen per month to 70,000 yen or more per month and depends on how nice accomodation you have and the location. There are frequently corporate housing offers or you could make arrangements to live-in with a Japanese family that is renting a room.
Most JETs pay between 20,000 and 60,000 per month (click here for exchange rate calculator). In the worst-case scenario, you might have to pay up to 6 months rent in advance. (This does not happen often.) On the other hand, many JETs live in very inexpensive subsidized housing. Fortunately, your remuneration is quite sufficient to cover whatever your housing costs might be.