Harajuku
The fashion center of Japan, where people go to see and be seen. I know it's a cliche, but here the little kawaii ("cutsie") girls dress in costumes, hang around Harajuku station and park, and even carry model release forms for photographers who want to shoot them...
(And that is pronounced tah-keh-shta, by the way...)
The more urbane Omotesando dori, where Europe's (and Japan's) high street fashion houses all reside...
Spotted: an iPhone4!