Toshihisa Negi is a recurring character in the Jujutsu Kaisen series and its prequel Jujutsu Kaisen 0: Jujutsu High. He is a curse user who used to be a commander in Suguru Geto's "family" of sorcerers. After Suguru's death, Negi and Manami Suda both decided to carry on his will by joining the entity who stole his body.

(Source: Jujutsu Kaisen Wiki)