Suimin Kairaku Kyōiku: Kegare o Shiranu Shojo no Mama Sono Shitai wa Kaihatsu Sareteiku

This Japanese erotic visual novel features a protagonist and his childhood friend being manipulated into having sex through erotic dreams.

The player takes on the role of a male student who regularly fantasizes about having sex with his childhood friend, Natsuha Hyuuga. Although he would not dare reveal his feelings to Natsuha, our protagonist eventually gets the opportunity of his dreams when his teacher, Saika Shidou, offers him the power to have sex with Natsuha whenever he wants. Little does he know that Saika is not human; she is an entity who uses the setting of the school to harvest energy from students, making them experience sexual dreams so she can feed off their energy. The player's decisions throughout the game determine how the story ends.