Japan statutory rape law is violated when an individual has consensual sexual contact with a person under age 13. At 13, Japans base age of consent is the lowest of any developed country.

What is the age gap for relationships in Japan?

In Japan, its 1.4 years (pdf). Thats a pattern seen around the world: Age gaps show up among heterosexual couples in every culture. Some evolutionary explanations have been proposed (older men may have more resources, younger women may be more fertile), but none are easily testable.

Is the age of consent in Japan really 24?

The Age of Consent in Japan is 13 years old. The age of consent is the minimum age at which an individual is considered legally old enough to consent to participation in sexual activity.