In a world where sorcery reigns supreme, the clumsy witch-in-training Louise Francoise le Blanc de La Valliere is known by her classmates at the Tristain Academy of Magic as "Louise the Zero." During a significant coming-of-age ritual, in which every student must summon a lifelong familiar, Louise reveals her clumsiness by accidentally conjuring a teenage boy from Earth. Now, whether they like it or not, Louise and her unwilling servant, Saitou, are bound to each other by the laws of magic for all eternity!