When planning a dive trip to Japan. It is better to rent from your LDS and schlep the gear over with you than renting in Japan unless you are Japanese or have a Japanese body type.
For both men and women:
Wetsuits typically are slimmer in the butt, hip and thigh with broad shoulders (V-shaped body type). BCs & wetsuits may measure the same around but the armholes & sleeves are cut for someone with a less "meaty" body type. So measurement isn't everything.
Dive Computers are more conservative too. (The pearlescent sky-blue Scubapro Extender is only available in asia & is actually manufactured by seiko/citizen and runs on their algorithm). The instruction manual & display will always be in Japanese.
The quality of the gear, as in all countries, will range from high to low and everything in between.