Summary: Ryou, who has just settled into his apartment, becomes intrigued with the noise of a female from the room next door. Because of curiosity, he eavesdrops his neighbor and which becomes his daily freak habit. The sound of phone calls, changing clothes, showering, and sex brings Ryou to have a degenerate vision of the neighbor. Ryou somehow also imagine himself is living with, and having violent and abnormal sex with her day by day. Ryou, who is prone to sickness, assumes that his neighbor is in the midst of a rendezvous with her lover. However, his neighbor Satsuki becomes increasingly worried with the daily phone threats she receives. Without fully understanding what is demanded of her, the unseen threats become a source of continued terror for Satsuki. As Ryou becomes closer to Satsuki, this behavior gradually starts to escalate. Only a thin wall separates the offender and his victim; boundaries are trespassed and each vignette complicates as they meet. The worst course of action develops as they start their rendezvous.