I just moved back to the states from Atsugi, its beautiful over there, make sure you hit up the electronics district of Tokyo, Akihabara. The best advice I can give you, go there, see as much as you can and keep a very open mind to the fact that Japan is still a very much closed society, and if you go into a restaurant or any were and get a crossed arm in the type of x don’t worry about it, just bow your head and walk away, there telling you your not welcome there, but not because your American, because they do not speak English and cannot service you..
Have a good trip.