This article discusses the history, cultural considerations, social stigmas and potential risks associated with cousins marrying each other in Japan. It is legal for cousins to marry each other in Japan provided that both parties are at least 18 years old without parental consent or 16 years old with parental consent. Cultural considerations to take into account when considering such a union include family expectations, societal opinion, financial implications, religious beliefs and personal feelings about the union. Potential risks associated with marrying cousins include increased risk of birth defects due to genetic similarities between both partners and increased risk of genetic diseases being passed down through generations within one family line if both partners share similar genes due to their close relation genetically speaking.