GVG-511 Older sister's real sex education Riona Minami

Riona and Shun are siblings who lost their mother when they were young and were abandoned by their father, leaving them with a large amount of debt. - One day, the uncle who used to take care of them finds their house and comes to visit. - However, the uncle's purpose is Riona's body, so he puts Riona to sleep and attacks her. - And Shun gets an erection when he sees that... - While the younger brother is confused, the older sister decides to teach him about proper sexuality.