[sarasi]

Buy a Tokyo guide book (e.g. Lonely Planet), read it from cover to cover, and then come back if you have any questions that weren't answered.

The more research you do yourself, the more fulfilling your trip will be. Also, do an internet search on "vegetarian in Japan" as there is a huge amount of information out there.

I live in Tokyo, and think that 15 nights here is too much. You should spend at least 3 days in Kyoto, also visit Hiroshima and possibly Himeji, and do overnight trips to places like Nikko and the Fuji Five Lakes. You don't have to climb Mt. Fuji, but wouldn't you at least like to see it?

Having to come back to Tokyo every night would be very restricting, and I foresee you running out of things to do after about a week.