Affordable gym in Shibuya area?

I live right by the Toritsu Daigaku station and want to join a cheap gym for the short term (2 months). Where can I go?

I see Curves has a branch close to where I am but they seem to only offer classes in teams.

Thanks.

How about using public-run sports center? Each ward in Tokyo has as least one sports center, which includes gym facility.

Meguro Ward Sports Center(2-4-36 Meguro, Meguro-ku/目黒区目黒二丁目4番36号)
http://www.city.meguro.tokyo.jp/shisetsu/shisetsu/sports_shisetsu/cent...
10 min walk from Meguro station or 15 min walk from Naka-Meguro station, 200 yen per day
Shibuya Ward Sports Center(1-40-18 Nishihara, Shibuya-ku/渋谷区西原1-40-18)
http://www.city.shibuya.tokyo.jp/eng/living/sports.html
6min walk from Hatagaya station or 15 min walk from Yoyogi-Uehara station, 400 yen per day