Cuckolding as foreplay for baby-making sex with her husband. Haru Shibasaki, whose husband suffers from ED, decides to be "cuckolded" for his sake. On a Saturday night, she whispers her cheating experiences into her husband's ear to encourage an erection, and they gently have sex. While feeling frustrated that she cannot make him climax herself, she develops complex feelings seeing her husband get rock-hard at the thought of another man. Unwillingly, Haru begins to get addicted to other men's cocks—