This article explores the history and legal definition of adultery in Japan, as well as the punishment for adultery, social attitudes towards it, its impact on divorce rates, and recent changes to the law. Adultery has been part of Japanese culture for centuries and is still largely seen as an acceptable form of entertainment among certain sections of society. It is illegal under Japanese law but carries with it a maximum penalty of one year imprisonment or a fine up to 500,000 yen. Recent changes made by the Supreme Court have made it easier for individuals who have been wronged by their spouse's infidelity to seek damages from them through civil lawsuits.