Yuka married a man with a child from a previous marriage. Her relationship with her stepson, Shinichi, was harmonious, and outwardly, she seemed to have no complaints. However, her husband's lack of passion prevented her from conceiving a child, and she herself was secretly frustrated and troubled. Then, her husband went on a long business trip, and she suddenly found herself living alone with Shinichi. Initially, things went smoothly, but as his physical affection gradually increased, Yuka began to feel something strange...