WHY?
Shibuya is the famous Tokyo crossing, a.k.a. The Scramble, and used by millions of people every year. Although it looks overcrowded, people hardly ever seem to bump into each other. They have natural antennae.
WHAT?
Holding hands in public was a strict no-no until recently, but fortunately traditions are there to be challenged. The young try to fight the old-fashioned ways of living and dressing. I have never seen as many extravagant hairstyles as in Tokyo.