Chu Shite Agechau: Oshikake Onee-san no Seikou Chiryou

Akira Segawa is a young man who, like everyone else, has natural sexual needs and desires. However, since he can't satisfy them with someone else yet, he has to find solace in masturbation.

One day, his stepsister catches him doing this because he forgot to lock himself in. To Akira's surprise, Yui turns out to be outraged by his behavior. She believes that such a beautiful body as hers should not be wasted. And she decides to help Akira become a real man and gain sexual experience. If she fails, you can always seek help from a family doctor.