Sumire has a secret that she can't tell anyone, which is... her buttocks have a consciousness of their own! Sometimes they will take control of Sumire's body, saying and doing things against her will. One day, Sumire's buttocks fall in love with the young man who moved in next door at first sight. And so, her buttocks take control and engage in lascivious actions to seduce him. Unable to resist the invitation from the beautiful girl, they engage in wild sex. And like that, even though she doesn't want to, Sumire's buttocks make her go to seduce him time and time again. Gradually, the pleasure that this young man brings conquers Sumire. Without the need for a reminder from her buttocks, she actively seeks out the neighbor and wants him to satisfy her sexual desires...