With marriage in mind, Aika and Shinichi have begun living together. While they are moving, the manager comes to visit, and he seems kind, but there is something suspicious about him. One day, while Shinichi is away, Aika invites the manager into her house to have a problem with the plumbing fixed. After eating the western-style sweets he brought as a gift, she is overcome with an intense feeling of sleepiness. When she wakes up, she finds the manager, drenched in sweat, pressed against her. Since the day when the manager gave her pleasure that surpassed her disgust, they have been having intense sex, with bodily fluids exchanging. Slowly, Aika's body and Kokoro are corrupted...