Based on the erotic game by Active.

Twelve years prior to it's discovery by Minase, the origins of the magic book with dark,sensuous powers is revealed. Initially owned by a female student, Takashiro, who, along with other curious students form the first magic club on campus. The club begins to use the erotic spells to carry out favors for fellow students, and vengeance. After underestimating the powers behind the book, Takashiro is taken out of the picture, as a new leader guides the club towards a darker course, one that will force school newcomer Kitami to make a dire choice.