J.Y. Interpretation No. 12 states that the custom of adopting a son for the purpose of marriage to the adopter's daughter, which means that the adoptee and the adopter's daughter are not biologically related, effectively constitutes the act of "taking in a husband" rather than "adoption" as meant by the Civil Code. If the son were adopted as meant by the Civil Code, the adoption relationship between the adoptee and the adoptive parents should be terminated before the adoptee marries the adopters' daughter.