After the death of his mother, Kazuya lived alone with his father. One day, returning home, he was shocked to find an elegant home-cooked meal and a young woman waiting for him. This was Miki, his father's rumored girlfriend. His father then announced, "I've decided to marry Miki," suddenly making her Kazuya's stepmother. Despite himself, Kazuya begins to feel an undeniable attraction toward the beautiful and alluring Miki. As the new family dynamic unfolds, Kazuya's emotions spiral into forbidden desire.