The series focuses on Asta, a young orphan who was raised from birth after being abandoned at a church orphanage on the outskirts of the Clover Kingdom along with his fellow orphan, Yuno. While everyone is born with the ability to utilize Mana in the form of Magical Power (魔力 Maryoku), Asta is the only exception as he compensates through physical training. Conversely, Yuno was born as a prodigy with immense magical power and the talent to control wind magic. Motivated by a desire to become the next Wizard King, an authority figure second to the king of Clover Kingdom, the two youths developed a friendly rivalry, acquired grimoires with Yuno obtaining a four-leaf grimoire held by the kingdom’s first Wizard King. Asta, despite his lack of magic, obtained the mysterious five-leaf grimoire, which contains the rare and mysterious Anti-Magic. But after he and Yuno each joined a Magic Knight squad as the first step to fulfill their ambitions, Asta finds himself facing a terrorist organization that is gathering magic stones to conduct a ritual to destroy the Clover Kingdom for its actions against the original inhabitants at the time of the first Wizard King.
An original video animation produced by Xebec that is based on the series was shown at the 2016 Jump Festa between November 27 and December 18, 2016.[14][15][16] It was bundled with the 11th volume of the manga, which was released on May 2, 2017.[17] A second original video animation was shown at the 2018 Jump Festa.[18]

