[Grumbo]

Yasakuni Shrine in probably not too exciting for you. Cool areas to check out are Akihabara (for the electronics), Shibuya (for the fashionable girls) and Shinjuku (for the stores and clubs).

I wouldn't assume most people speak English. If you have trouble, look out for high school- or college- aged people as they are likely to have had some English classes in school.

As for any adult entertainment, that might be a problem. Almost all of those places do not allow foreigners inside as they are worried about AIDS. It is totally legal to discriminate against foreigners over there.