Even after remarrying, Yuka still struggled to connect with her stepson Tomoki, constantly trying to build a closer relationship. However, Tomoki was going through a complicated adolescent phase, and her kindness went unreciprocated. Unbeknownst to her, Tomoki had actually fallen in love with Yuka, but he couldn't bring himself to confess his feelings. One day, Tomoki accidentally discovers Yuka having sex with his father. In that moment, he is shocked by the sight of Yuka's sensitive nipples being stimulated—her body writhing and convulsing with pleasure—leaving him frozen in place. The image deeply imprints on his mind, becoming the catalyst that awakens his suppressed desires.