Madoka is living apart from her husband, who is working in another city, together with her two sons, Taichi and Yoichi. The eldest, Taichi, is responsible and mature, but the younger son, Yoichi, has not decided his future path, leaving Madoka constantly worried. One day, overwhelmed by Yoichi's constant smartphone use, Madoka confiscates his phone. That night, Yoichi sneaks into her bedroom to retrieve it. There, he encounters a side of his mother he's never seen before—a sensual, alluring woman revealed only in the darkness of night.