The series focuses on Asta, a young orphan who was raised from birth after being abandoned at an orphanage 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. He tries to gain magical power 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. Yuno obtains a legendary four-leaf grimoire held by the kingdom's first Wizard King. Asta, despite his lack of magic, obtained the mysterious five-leaf grimoire (which can't be clearly identified by others because it's worn out), which contains mysterious elf swords and rare anti-magic. Afterward, he and Yuno each join a Magic Knight squad as the first step to fulfill their ambitions.