[ChisaChi]

A friend of mine who is sort of vegan (no fish, meat products or eggs, but fine with milk and cheese) survived fine in Japan - but it can be hard to find a place to eat and can be more expensive. She ate a lot of Italian food, which of course is a lot more expensive than the local stuff. Most of the restaurants that I went to didn't have any vegetarian friendly options. But as long as you're not too fussy and keep in mind that you might have to look a bit harder to find a decent place to eat, it's definitely possible to survive.

I stayed in a great hostel in Tokyo for 3000 yen per night, I'd imagine there would be similar places around other major cities for similar prices. The staff were pretty nice with suggestions of good (and cheap!) places to go and things to do, so it's worth talking to the people you meet.

If you're traveling to heaps of different cities then the JR Pass is great. Just remember it might not be so useful for traveling within a city, since a lot of the trains there aren't JR. But if you're going on a lot of bullet train rides it saves heaps.

In the cities I found that we could easily walk the distance of one train stop in 15 minutes or so, which was fun for exploring. Doesn't help if you're going somewhere far away, but our hotels usually seemed to require us to catch one train for one stop, then switch to another train system from there, so it saved us that 130yen each trip for the first train.

Oh and try checking the websites for the hostels and places you're going! I printed some coupon from the website of the place we went skiing in Karuizawa even though it was all in Japanese and I had no idea what it was for, and we ended up getting discounted gear hire and lift pass and a free lunch.