Yuji, the son of a concubine, lost his parents and was taken over by his legal wife, Hanahoko. Kahoko was not blessed with a child and was treated coldly by her father-in-law because of that. Kahoko's younger sister, Ayaka, who was worried about her, proposed a plan to use her Yuji's sperm to make Kahoko pregnant with her husband's child. She was Kahoko who refused at first, but her female instinct begins to tingle with her young and powerful cock.
