Now it's time to unwrap your present
And then he contributed to the corruption of a minor...
https://www.worldatlas.com/articles/what-is-the-age-of-consent-in-japan.html
Site's out of date (2018) and does not reflect the nationwide age of consent being raised from 13 to 16, but that's just for it not to be rape. Corruption of a Minor laws make the actual age of consent higher.
Age Of Consent In Japan’s Prefectures And Territories
Most of the prefectures in the country have obscenity statutes or laws against corruption of minors. The age of consent in the prefectures ranges from 16 to 18 years, and it is illegal to engage in sexual activities with partners who are below this age unless a parent approves of the romantic relationship. In Tokyo, for example, a person has to be at least 18 years to agree to have any form of sexual relations. In both of Japan’s territories, Okinotori Islands and Marcus Islands, the local age of consent is 13 years.
Close In Age Exemptions
The age of consent in Japan has no close in age exceptions. Partners who engage in sexual relations with persons aged less than 13 years can be prosecuted for statutory rape in spite of the age difference, even if the younger partner consented. The absence of close in age exemptions also means that there is no legal protection for two individuals who willingly give in to intimate relations when they are under 13 years of age.