Koharu struggles with her guilt as she continues to be abused by A-kun's father and brother. After being subjected to a powerful aphrodisiac and a cruel challenge, her resolve completely shatters, and she embraces her new role as the household's communal plaything. Ultimately, Koharu betrays A-kun, casting him out of the house to fully surrender to the hedonistic desires of the "beasts," leaving A-kun to watch her degradation from afar.