The continent of Halkeginia is tumultuous—a place where the various kingdoms, princedoms, dukedoms, and fiefdoms strive against each other to expand their domains. The nobility scheme and plot among themselves to gain influence to their lieges or to even foreign lieges. In the middle of Halkeginia is the small but important kingdom of Tristein. The most notable fact about this kingdom is the Tristein Academy of Magic where nobility from all over the world come to study magic so they can become magi. Although friendships will form across national boundaries at this school, will they survive the politics and games of the world at large once they leave?

Louise is a student at Tristein Magical Academy. She is known to be quite a screw up when it comes to her magic. One day, a ceremony takes place where each student is to call forth a being or entity that will become his or her familiar. For Louise, her familiar comes in the form of a boy named Hiraga Saito. Somehow, he managed to get transported from his world into hers, and shortly after became her familiar.

Due to the author Noboru Yamaguchi's illness, Zero no Tsukaima was discontinued in 2011, only publishing 20 volumes out of the 22 planned. In 2015, the official site announced that it would resume publication until the series' completion. Yamaguchi died in 2013 at the age of 41, after more than two years of fighting cancer. The remaining plot and ending of the series were assigned to the series' editors by Yamaguchi on his sickbed.

The series has been licensed in Brazilian Portuguese by NewPOP Editora.