For a night out that you will never ever forget, head to the Roppongi district of the city, where the drink flows almost constantly throughout the week, and the neon lights make the streets bright as day even in the wee small hours of the afternoon. Practically every taste and pleasure can be yours in Tokyo, although its worth noting that in the Hostess bars a single beer can cost around £50 simply for the privilege of having a beautiful lady join you for a few minutes of stilted and rather one sided conversation - in most places around £1-5 is the norm for a bottle of imported lager.
Clubs are garish pleasure palaces, although the locals don't much like people dancing unless they're in time with the carefully choreographed routines that proliferate.
Rather tastelessly named in light of the Sarin gas underground attacks the city lived through a few years ago, Gas Panic is legendary in Japan, and is the place to go out in the evening, every evening.