After a marital argument, Manami's father-in-law suddenly shows up at her home and asks to stay for a few days. As a result, he notices her sexual frustration. Pretending to mistake her for his wife, he makes advances toward her. Unsatisfied in her marriage, she gives in, pretending to be his wife, and indulges in the forbidden sex. Midway through, she realizes his true intentions, but by then it's too late—she's already been filled with his cum. From that point on, she continues to submit to his desires, her body repeatedly taken against her better judgment.