Sumire has a secret that she can't tell anyone, that is... her buttocks are self-aware! Sometimes it will take control of Sumire's body, saying and doing things against her will. One day, Sumire's buttocks fell in love with the young man who moved into the room next door at first sight. And so her buttocks took control and performed lewd actions to seduce him. Unable to resist the invitation from the beautiful girl, they engaged in passionate sex. And so, despite not wanting to, Sumire's buttocks compelled her to seduce him time and time again. And gradually, the pleasure that this young man brought conquered Sumire. Without the need for a reminder from her buttocks, she actively sought out the neighbor and wanted him to satisfy her sexual desires...