The main character, Kusuki, have a boyish childhood friend named Satsuki. Ever since Kusuki saved Satsuki from moutain accidents, their family has been attached to him. One day Satsuki finds an erotic book, strangely enough, the book contains similar story about them, Satsuki grasped the situation decided to tease him. Kusuki who had zero resistance against her eroticsm suddenly jumps into her. They eventually became a lover. But looks like Satsuki will have a rival. Chisa Kanbara who rumoured had Extra Sensory Perception, is in love with Katsuki, in fact she has been holding her feelings towards him since they were young and now it’s reached to the state she can no longer hold her feelings anymore. Chisa put Kusuki unconscious and decided show her true self.