Asta and Yuno were abandoned together as babies in baskets in the same church the same day, and since then they have been inseparable. When they were children, they promised that they would compete with each other to see who would become the next Wizard King. However, as they grew, some differences between them became clear: Yuno was a magical prodigy, while Asta could not use magic at all.
The series focuses on Asta, a young orphan who was raised from birth after being abandoned at the doorstep of an orphanage in Hage village along with his fellow orphan, Yuno. While everyone is born with the ability to utilize Mana in the form of Magical Power, 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..
Black Clover Episode 145