Makoto, the only son born into a married couple suffering from emotional detachment, grew up starved for his mother's affection, never learning how to properly receive it. One day, by a friend's prank, he notices the soft hair gently growing under his mother's arms, and is deeply shaken by its presence. From that moment on, his perception of her shifts completely, transforming her into a sexual object in his mind. Unable to suppress his overwhelming desire, Makoto forcefully pins his mother down. As his twisted feelings grow deeper, he plunges into increasingly lewd and humiliating acts with her. His relationship with his mother gradually deteriorates, and his mind can never return to the way it once was.