We may point out three important points about family. First, family is the starting point of the birth of vertical human relations. Second, such vertical human relations are not limited to a specific family but are, though informal, a kind of social phenomenon that has attained a social consensus. Third, the ethical value of vertical human relations formed through family may vary according to each people’s historical situation or customs, and the enforceability of such relations based on social consensus may be different. This study proposes to discuss the three issues through stepmother stories handed down in Korea and Japan. I discuss that the typical pattern of stepmothers’ evil deeds is different depending on whether the former wife’s child is a son or a daughter. That is, unconditional sacrifice is forced on the former wife’s daughter through domestic labor, extramarital pregnancy, etc. and on the former wife’s son through his sacrifice to cure his parent’s disease. In addition, such typical patterns mean the deprivation of the deprivation of the former wife’s daughter’s position at home and the deprivation of the former wife’s son’s position in society. In order to restructure the vertical human relation of the family, the stepmother has to deprive the former wife’s children of their positions based on the established family relation. In this sense, stepmother stories reveal violence that is either hidden in families built on vertical human relations or tabooed in normal families.