There are moments when a man does not want anyone to be disturbed. It was one of those moments for our protagonist, Yukiko Mamiya. He has an obsession with 'Bukkake' and it was something he would rather keep to himself.

After having a rather intense session his door bell rings. He quickly goes to answer it and finds his cousin Miyayuki there. In his haste he fails to cover his lower half. But instead of shock, Miyayuki seems to be interested. She watches him closely until he splatters her face with his cum.

From now on he finds his private sessions are now with different women showing him their bodies.

This new masturbation life for Yukiko begins -
Source: VNDB