Sumi had a secret she couldn't tell anyone. Her instincts unconsciously triggered movements in her ass, drawing her awareness away from her own will and fixating it on her backside. One day, she fell head over heels for a man who moved in next door. As her attention became increasingly focused on his ass, Sumi found herself irresistibly drawn into its allure. Her mind gradually came under the control of his backside, and before she knew it, she was helplessly attracted to him, even though she didn't fully understand why.