College student Kousuke leads a normal life filled with classes and video games until a vivid nightmare leaves him questioning his own nature. His routine shatters when the beautiful goddess Fauna appears before him, revealing the demonic potential he harbors and initially aiming to eradicate it. Choosing a different path to subdue the inner evil, Fauna enlists the help of her older sister Jordh in a series of intimate rituals. However, the arrival of the cunning little devil Natsuki introduces unexpected twists to their efforts.
