In a magical world called Halkeginia at the Tristain Academy for magicians, Louise Vallière heads to class on her first day as a second year student. Her teacher asks her to perform a simple spell: to change pebbles into brass, though her peers mock her with the nickname "Zero". As soon as she casts the spell, the room explodes. Despite being from a famous magician family, Louise has a "Zero" percent success rate casting spells. On the day of the familiar summoning ceremony, Kirche summons a fire salamander; Guiche summons Verdandi, a large mole, but Louise summons a human being, Saito Hiraga, from Tokyo, Japan who cannot understand what Louise is saying. Louise is disappointed but cannot break the ritual's tradition, so she makes a contract with Saito by kissing him and runes appear on his left hand. Louise tries to shut him up by performing a silence spell which backfires and allows Saito to speak and understand Louise's language. Saito thinks he has been kidnapped until he sees the two moons in the sky and realize he is in another world.