[masaegu]

As for manga/anime-related shopping, remember the names of these two sections of Tokyo: "Akihabara" and "Ikebukuro". Those are currently the hottest areas for the otaku with numerous entire buildings dedicated to manga/anime (new and used) and related goods such as stationary, stickers, t-shirts, cell phone chains, confectionaries, etc..

In Akihabara, just follow the otaku-looking kids from the train staion, it will take you where you want to go. In Ikebukuro, however, you might have to ask someone where "Otome Road" is. That is the street you want to go to and it's about a ten-minute walk from the station. In Ikebukuro, I always go to the shop (actually rather a 7 or 8-story building) named Animate when I buy gifts for friends abroad.