Son Kosuke is shocked when his mother, Yuri, announces her remarriage. Though grateful to the woman who raised him single-handedly, he had always viewed her strictly as a mother. However, after meeting her fiancé, Maruyama, and observing his demeanor and attitude, something stirs within Kosuke. Feelings of loss at the thought of his mother belonging to another man, anxiety over her new life, and an intense desire to keep her to himself begin to surface. This encounter becomes the turning point where he starts seeing his mother not just as a parent, but as a woman. A story delving deep into shifting emotions and inner conflict, exploring forbidden desire and the blurred lines of familial bonds.