Asahi lives with her kind husband Koichi and her father-in-law Haruo. Her father-in-law Haruo is kind to Asahi and has spoken of his desire to have a grandchild soon. However, Haruo knows that Asahi's relationship with Koichi is bland and leaves her unsatisfied. One morning, as Haruo sees Asahi off as Koichi leaves for work, he attacks him... And from then on, every day when they are alone, Haruo repeats obscene acts. As this happens every day, Asahi begins to awaken to a pleasure that he never got from Koichi...