Minase, a high school student, found a book of magic in an isolated room in his school. He started practicing black magic that has extreme sexual effects that benefited him and some of his friends. Intrigued, Minase got deeper and deeper into using the craft, not realizing the evils that will come forth. Eventually, the origins of the book was revealed, and so did the incident twelve years ago on the night of the Walpurgis, the night when the power of evil is at its strongest. After coming to his senses, Minase struggles to get himself out of the darkness that he had put himself into.
The animation is very good, the erotica delightful, the voice acting however is annoying. Thankfully it gets a lot better in Origins and New Testament but in all 6 Bible Black episodes it's pretty awful, just badly cast voice actors.
However, if you ignore the acting and just enjoy the film it is enjoyable with a decent story arc.