Aimi, a high school girl, is secretly photographed in compromising positions by a student teacher and coerced into engaging in bizarre sexual acts. Living constantly in fear and anxiety, deep down she longs to confide in someone. Suddenly, her stepbrother appears and begins intruding into her private life—sneaking into her room, spying on her while she masturbates, and indulging in his own desires. Though confused by his actions, Aimi secretly feels grateful, believing he's trying to rescue her as his beloved little sister. Unaware of his true identity, she starts exchanging emails with a mysterious online friend, pouring out her inner struggles. But what is the stepbrother's real intention? And what ultimate fate awaits Aimi?