Taken into the family as her husband's stepchild, Aoi suffers under the constant hostility of her older stepbrother Hikaru, gradually opening her heart only to younger brother Nobuo. As Nobuo begins to develop feelings for her, the two eventually become lovers. But this relationship is part of a trap orchestrated by the brothers. Aoi's life as the "obedient stepmother" begins... A dramatic story unfolds, entwining the brothers' schemes and turbulent emotions.