In the Clover Kingdom, magic decides a person's class, career and worth. Asta, an orphan born with none at all, refuses to accept that verdict, and when a battered five-leaf grimoire grants him swords that cancel magic rather than cast it, he finally has a weapon equal to his ambition. Alongside his rival and fellow foundling Yuno, he joins the Magic Knights - Asta into the disreputable Black Bulls, Yuno into the elite Golden Dawn. What starts as squad rivalry and rank-chasing widens into conflict with the terrorist cell known as the Eye of the Midnight Sun, ancient elven grievances, and devils bargaining from beyond the veil. Across 170 episodes the show grows from gag-heavy training bouts into kingdom-spanning warfare, while Asta's hoarse, unbreakable optimism drags a squad of outcasts toward respect.
Asta and Yuno are left at the same church as babies and raised as brothers in a poor border village. Both swear to become Wizard King, the kingdom's strongest mage. At the grimoire ceremony Yuno receives a legendary four-leaf book while Asta receives nothing - until a black five-leaf grimoire chooses him, arming a boy with zero magic power with anti-magic blades and a body trained to compensate.