A family that appears to be living harmoniously: a married couple entering their third year of marriage and the husband's younger brother. However, for Airi, the wife, life has become increasingly brutal. Whenever her husband leaves the house, her brother-in-law forcefully demands invasive physical acts from her. Though Airi struggles to resist, she is quickly overpowered, gradually losing her sense of self. The abuse escalates relentlessly, eventually spreading to the brother-in-law's friends. Beneath the name of family, a deep darkness spreads.