109: ichi maru kyuu
The mecca for fashionista is 109, a round shaped building in Shibuya.
This is the ultimate fashionista experience!
The sales-Gyaru that you meet there are in fact seasoned businesswomen that are experiencing the fashion that they create, selling them with a lot of tact and fun, and they also keep strict accounting... Any would-be sales-person should make a training there!
You need to take your time, and spend at least, half a day inside, go around the shops, try things on, take pictures, buy them if you have the right age so that you do not look ridiculous (like me)... it is really fun!