Asta and Yuno were abandoned together as babies in baskets at the same church on the same day, and have been inseparable since. As children, they promised that they would compete against each other to see who would become the next Wizard King. However, as they grew up, some differences between them became plain - Yuno was a magical prodigy, while Asta could not use magic at all. In a country where magic is everything and athletic ability is nothing, Asta tried every day to provoke even the simplest magic out of himself with physical training and loud proclamations of his will.
At age 15, during the group ceremony where three-leaf-clover grimoires of different designs float down to each person, Yuno receives a spectacular book with the legendary four-leaf clover, while Asta receives nothing at all. Later, however, when Yuno was surprised and trapped by a fallen magic knight, the truth about Asta's power and determination was revealeda dark-covered, obscurely patterned grimoire broke out of the ceremony tower and came before him! This "black clover" book of anti-magic had a five-leaf clover on the cover, even though Asta himself did not see it as it lit up briefly just that one time while he defended his friend.
Now the two friends, the four-leaf-clover genius and the no-talent with the hidden black clover, are heading out in the world, competing for the same goal...