Maki, who was angry at her husband's cheating, decided to take her son Keita and go to her sister's house for a while. However, his older sister Ayano and his son Takahiro have a forbidden relationship, and Keita, who has been inspired by looking into it, asks Maki for a relationship. Such two sets of mother and child are under one roof ... At some point, the relationship is jumbled, and the forbidden mother-child swap full of lust begins! !
