The Familiar of Zero (ゼロの使い魔, Zero no Tsukaima?) is a fantasy and comedy-oriented series of Japanese light novels written by Noboru Yamaguchi and illustrated by Eiji Usatsuka. The story features several characters from the second year class of a magic academy in a fictional magical world with the main characters being the inept mage Louise and her familiar from Earth, Saito Hiraga. The series has been adapted three times as an anime series. The first season aired in Japan between July and September 2006 produced by the animation studio J.C. Staff and directed by Yoshiaki Iwasaki. The second season, entitled Zero no Tsukaima: Futatsuki no Kishi, was directed by Yū Kō and aired in Japan between July and September 2007. A third anime adaptation, titled Zero no Tsukaima: Princesse no Rondo, is produced by J.C.Staff, with Yū Kō as the director, and aired on Japanese television between July and September 2008. A manga version drawn by Nana Mochizuki began serialization in Media Factory's manga magazine Monthly Comic Alive in July 2006.
On April 21, 2007, Geneon announced that they have picked up the English dubbing rights of the first season of the anime series and will be under the title The Familiar of Zero. The announcement was made at the 2007 Anime Boston convention. On July 3, 2008, Geneon Entertainment and Funimation Entertainment announced an agreement to distribute select titles in North America. While Geneon Entertainment still retains the license, Funimation Entertainment assumes exclusive rights to the manufacturing, marketing, sales and distribution of select titles. The Familiar of Zero was one of several titles involved in the deal.
Saito Hiraga, the main male character and primary protagonist of the story, is from modern-day Earth (specifically Tokyo, Japan). While walking down the street a portal opened in front of him, and when he touched it he was sucked through, landing in the Tristain Academy of Magic. At first, Saito had no idea where he was, and was thoroughly disoriented. His attitude is generally carefree yet he blows up easily when anyone he cares for is in danger, particularly Louise. Though he at first wishes to return home, he adapts to his strange new situation relatively quickly.
There are runes inscribed into Saito's hand as a result of his being bound to Louise. They read or Gandalfr (ガンダールヴ Gandāruvu?, actually "Gundolf"). These runes glow when his Gandalfr powers activate. As a Gandalfr, a familiar who exists to protect a Void Wizard, Saito has the ability to use any object that was made with the intent of being used as a weapon at an extremely high level of skill. He also becomes significantly stronger, faster and tougher. This physical augmentation fades more or less instantly when he stops using the power, which can result in him falling unconscious if he had been previously wounded. He is said to be the left hand of god.
His partner, the talking sword Derflinger, was also the partner of the Gandalfr six thousand years previously. Saito protects Louise with a passion, a result of both his duty as a Gandalfr and his feelings for her. He eventually falls in love with Louise, despite the abusive way she treats him.