In reply to Cheryl:
I used to climb at T-wall when I was staying in Tokyo because it was very close to my residence. At the time they had 3 locations in Tokyo and now I believe already five.
http://twall.jp/
Good thing about T wall is that you can use your membership card at all the locations (both bouldering and lead) so you don't have to keep on signing up and paying the membership fee.
(Japanese gyms have a membership system which requires you to pay a one time only membership fee usually between 1000 /2000 yen, very annoying for singel visits). At the Pump branch I know you can get in without paying membership when identified as a tourist, or at least I could in Yokohama.
The best, by far, gym I've been to for both climbing and bouldering is Climbpark Basecamp by Yuji Hirayama. It's a bit outside of Tokyo, but easily reached by the trains ( Seibu Ikebukuro Line)
http://b-camp.jp/iruma/
They have recently opened a bouldering gym in Tokyo which I've never been to
http://b-camp.jp/tokyo/
Dai Koyamada has a bouldering gym between Tokyo and Yokohama which I also liked
http://www.project-climbing.com/