GVG-511 - Older Sister's Real Sex Education - Rio Na Minami

After their mother passes away and their father abandons them with massive debt, siblings Rio Na and Shun are left alone. One day, their uncle finds them, but his true motive is to prey on Rio Na. Watching his sister being assaulted, Shun finds himself strangely aroused. Realizing her brother's confusion, Rio Na decides to take matters into her own hands and provide him with a proper, hands-on sex education.