This is a good backstory it is a great watch and both episodes give a backstory to Bible Black. If intrested in Bible Black watch this before the main series there is enough enjoyment of hentai scenes both yuri and normal and enough 18+ material. Spoliers below The club is created by three women Rei, Saki and Renito they first form by reading palm cards trying to form a witch craft club at school. The counciler denies the wise and the three girls put a spell on her and her friend. The counciler then goes out on a revenge while trying to summon the devil. The sacraficed women then makesa deal with the devil, while Renito and her are the only survivors.