A woman named Mei finds herself taking care of her husband's co-worker's son, Hiroto, while he's away. Despite being confused at first, she enjoys the new life with her husband until she realizes that Hiroto has his sights set on her massive breasts. He transforms her into a semen tank for his shota needs and even involves two of his friends in their daily breeding training sessions. As they continue to impregnate her, Mei becomes increasingly aroused by her newfound role as a breeder and falls deeper under the control of these young studs. Note: Content may vary depending on distribution method.