This article explores the legal, religious, and social implications of an uncle marrying his niece in Japan. According to the Japanese Civil Code, marriage must be based on mutual consent between two parties who are both at least 18 years of age and not closely related to one another. In feudal times it was common for relatives to marry one another, however this practice was abolished during the Meiji period when Japan began modernizing its laws. Today, it is illegal for close relatives such as an uncle and niece to marry one another due to the country’s strict marriage laws which forbid marriages between people who are too closely related by blood or adoption. The majority of religions practiced in Japan do not condone marriages between close relatives either due to their own beliefs or because they adhere to civil law regarding marriage regulations. Such unions are generally frowned upon by society at large in Japan today. If found guilty of violating these laws, punishments can range from fines all the way up to prison time depending on severity of offense