Wataru realized he was becoming more attracted to his girlfriend's mother, Kyoko, her beauty and sensuality captivating him more than his girlfriend of two years. Meanwhile, Kyoko, who had been suffering from sexual frustration since her divorce, would watch her daughter affectionately cuddling with Wataru, feeling both fondness and a quiet envy deep inside. One day, as Kyoko stepped out of the bath, she unexpectedly caught Watar rummaging through her underwear in the changing room. Caught completely naked and staring at each other, Kyoko panicked while Watar hastily fled. From that moment on, a taboo-laden love triangle gradually intensified—entwined emotions drawing the two deeper into an illicit attraction, their forbidden bond steadily unfolding.