hi chinita8! this time, i'll be staying in shibuya excel but it's a bit expensive. though the tokyo metropolitan hotel in ikebukuro is an excellent alternative. subway is a 3 min. walk and shopping options are endless, and restaurants are plentiful.
must see places: harajuku on a sunday- a lot of cosuplayers showing off their duds
akihabara-electric town-especially if your a techie or if you wanna see otakus/otomes (geeks who are obssessed with anime/manga)
imperial palace garden
asakusa temple at night
odaiba-check out miraikan (museum) to see asimo (robot) and so much more high tech stuff
must do:day trip to fuji/hakone- being able to ride the shinkansen was fun!
tokyo disneyland or sea (only if you haven't been to the disney world in orlando coz you would be disappointed. a good alternative is the sanrio puroland)
tokyo tower(only if you haven't been to paris. nice views of tokyo. check it out during the night. nightlife abound in roponggi)
go to a maid cafe/butler cafe-just for the experience!
shop til you drop in ginza, shibuya, ikebukuro, and omotesando-especially the japan exclusive brands like garcia marquez, cecil mcbee,burberry blue label, etc. chacott cosmetics, sanrio(they only sell stuff made in japan),comme des garcon, samantha thavasa, etc. (btw, for cosmetics, try the deparment stores for brands like rmk and matsumoto kiyoshi drugstore for the cheaper ones)
tobu and seibu department stores in ikebukuro-largest in the world
eat sushi at tsukiji market
namjatown in sunshine city ikebukuro-gyoza, ice cream, and crepe theme park
hope this helps!