Title: Bible Black Gaiden
English title: Bible Black Origins

After their rejected request to create a formal student magic club, Hiroko Takashiro, Saki Shidou, and Rie Morita are forced to continue practicing witchcraft in their free time only. One day, Rie comes across a dusty, hand-written book. Found on a sales pile in an antique shop, the manuscript seems to be nothing more than a foreign curiosity.

Upon translating the book, the girls discover simple spells designed to bend an unsuspecting victim to the user's will and impose one's sexual desires on them. Realizing they have come into possession of a mighty weapon, the group begins fulfilling different requests of other students—be it for love, vengeance, or sexual desire. As the situation spirals out of control, the magic club gradually transforms into a cult of blood, lust, and human sacrifice.