It's been three years since she married her current husband. They happily gave birth to a child, but her husband gradually stopped coming home, and Momo felt increasingly lonely. The one who always filled the void in Momo's heart was her husband's stepchild, Masashi. In fact, Momo and Masashi's relationship didn't just start, it had been going on for two years already. Behind her husband's back, her mother and stepson had been strengthening their forbidden bond. Is the child Momo has given birth to her own, her husband's? Or is it with her stepson...?