Tonight, Riona is home alone, left to babysit the house. Her neighbor, an older man, knows she's by herself. Using the excuse of delivering a package, he enters her home and gradually closes the gap between them through conversation. Seizing a moment when she's not looking, he slips a drug into her drink and finally takes the long-awaited action. From that day on, he repeatedly sneaks into her house whenever she's left alone, easily toying with her pure and innocent body.