Tsuchie Takeshi dreams of playing with Hikari-chan from their childhood. He recalls her as a kind and sweet girl. However, one day on his way home from school, Takeshi is abducted and taken to a huge house, where he discovers that she has become an arrogant, violent dominatrix. Furthermore, she claims that he promised to marry her! How will he adjust to her new personality and to living with her as the new son of her prestigious family?