Koji, who returned to his parents' house, felt uneasy about the awkwardness of his brother's couple. When I heard the story, it seems they are trying to get pregnant and repeating intercourse every night. I was trying not to get involved, but I happened to encounter that scene... Even though she noticed me, I was captivated by my sister-in-law, Jun, who showed me her lewdness. Jun, who desperately wants a child, asks Koji for sperm, saying that he is her brother. Unable to resist her, who repeatedly asks me while covered in sweat, I end up releasing a large amount of semen deep inside her vagina...