On the weekend, the brother and his wife spend their time visiting their parents and cute sister Kumamiya. Having just met his sister, the brother was extremely surprised that his little brother had now become a beautiful adult girl, which made his lust begin to appear. During the time of family gatherings, eating and talking happily, he only focused on her sister's breasts because it was too attractive. Then, taking the opportunity for everyone to rest, he began to do the miserable work of raping his sister, although he resisted fiercely, but he still couldn't turn the situation around when he was too strong, and in the end, she had to endure in helplessness. After that, she didn't tell everyone in the family and decided to keep quiet, perhaps this was also the reason why he continued to humiliate her again and again, it was a wrong decision.