Yuka's husband became disabled due to complications from an accident. While constantly worrying about him, she continues to support him every day. One day, her part-time store manager visits her home, claiming he's returning a forgotten item. But his true intention is to seduce Yuka. He slips an aphrodisiac into her drink, and her body gradually begins to change. As her curiosity about infidelity awakens, she becomes obsessed with the manager's cock, beginning a series of days filled with repeated creampie sex.