Asta is an orphan raised under the care of a church in Hage after his mother abandons him on the church’s doorstep. After turning 15 years old, Asta receives a five-leaf clover grimoire with an Anti Magic devil inside. He joins the Clover Kingdom’s Black Bull squad of the Magic Knights and becomes a 1st Class Senior Magic Knight and temporarily a Royal Knight.

Asta is a young man of short stature with an exceptionally muscular build. He has green eyes and messy, ash blond hair with bangs in front of his forehead and a single strand protruding upwards from the center of his head. He keeps his hair together with a black headband, which has the gold-colored Black Bull insignia and has a red-colored four-pointed star with three stitches on the back of it. He has numerous scars all over his body from his strenuous physical training and a large scar on his abdomen where one of Mars’s Harpes pierced him.