According to AAMC (the MCAT test maker), there are 2 MCAT test centers in Japan. Most testing centers are located inside a college or university. You can select a testing location that is nearest to you. Please note that you are able to choose a test center when registering for the MCAT.
OSAKA,JAPAN #1
NAKATSU CENTER BLD.,7F
1-11-1 NAKATSU KITA-KU
Telephone 06-6376-5811
OSAKA, Japan 531-0071
8601, TOKYO, JAPAN#1
Ochanomizu Sola City Academia 5F,
4-6 Kanda Surugadai Chiyoda-ku
Telephone 03-3258-9151
TOKYO, Japan 101-0062