[JUQ-253] The cowardly brother let his friend rape his sister

A sex movie of Rio Kuriyama, a girl who lives with her husband and her younger brother, but the younger brother is shy and has a strong friend. When he comes to visit, he falls in love with his friend’s older sister and rapes her. Knowing that he is raping his sister, the younger brother is helpless and lets his friend fuck his sister even though he knows that it is a sin against his brother-in-law. The older sister gradually falls in love with the strength and health of the young man and they fuck each other every day until one day her husband comes home and discovers the painful truth….