Asta and Yuno were abandoned together at the same church 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 the differences in their abilities became considerably noticeable. Yuno was a genius in his magic control and power, whilst Asta possessed no magic at all so he trained his physical body as much as possible in an attempt to make up for his lack of magic. Having received their Grimoires at age 15, Yuno unexpectedly got one with a four leaf clover symbol on his whilst Asta unfortunately did not even get a Grimoire at all. However, when Yuno was threatened, the truth about Asta's power was revealed, he received a five leaf clover Grimoire, a "black clover". Now the two friends are heading out in the world, both seeking the same goal.
