In Shinjuku, the first challenge is getting out of the station. Said to be the world's busiest; traversed by approximately 3 million commuters a day, Shinjuku has been a Japan Railways stop since 1885. The Chuo, Keio and Odakyu train lines as well as subway stops joined later, and the depot morphed into a dizzying, multileveled warren of platforms, shops and restaurants.

Frenzied by day, the station quietens down shortly after 1 a.m., but for the snores of about 200 station employees who bunk there, as they've kind of missed the last train home.

The ward of Shinjuku has two such personalities, one staid and the other edgy. Politicians and peep-show pros, sky-scraping pinnacles and "Piss Alley," street performers and geisha -- they all share the area.