Congratulations! The 50th installment in the series! When his mother's friend Hiroka comes to stay, Yuzuru is reminded of the sexual awakening he felt with her, and secretly feels excited. That night, as they talk about old memories, Hiroka gets completely drunk... Feeling a twinge in her crotch as she watches Yuzuru grow up, she can't help but rape him in his room. After that, the two of them continue to enjoy their sweet relationship, hiding it from her mother. However, Hiroka feels guilty about continuing her adulterous relationship with her friend's son...