A young Devil Hunter belonging to Public Safety Special Division 4. Originally, he lived a life of poverty as a private Devil Hunter, but died due to his employer's betrayal. He was resurrected as "Chainsaw Man" through a contract with Pochita, the Chainsaw Devil, and joined Public Safety Special Division 4 after being scouted by Makima. He is honest about his desires. He likes Makima, who was the first person to be kind to him, but he is also starting to take an interest in Reze, whom he met by chance while taking shelter from the rain. About Chainsaw Man... He attacks by slashing devils using chainsaws that sprout from his head and both arms.

A woman who manages Public Safety Special Division 4 and is Denji's boss. She is a Devil Hunter directly under the Chief Cabinet Secretary, and ordinary Devil Hunters are not even allowed to know which devil she has a contract with. She met Denji while heading to subjugate the Zombie Devil and scouted him into Public Safety.

Makima's subordinate working in Public Safety Special Division 4, and Denji's senior by three years. He harbors an intense hatred for the Gun Devil, which led him to become a Devil Hunter. He has contracts with the Curse Devil and the Future Devil.

The Blood Fiend and a member of Public Safety Special Division 4. A "Fiend" is a devil that has possessed a human corpse; normally they are targets for extermination, but because she possesses relatively high intelligence and rationality for a Fiend, Makima is having her undergo training as a Devil Hunter. She is partnered with Denji but is selfish and prone to running wild. Her cat, Meowy, is her only friend.

A member of Special Division 4. A unique devil who harbors no ill will toward humans, but anyone who touches him directly will have their lifespan drained away.

Excels at information gathering and is researching Koro-sensei's weaknesses. He has a quiet and gentle personality. However, he actually possesses a superior talent for assassination.

The person who came up with the name "Koro-sensei." She has a strong complex about her flat chest. She is a huge fan of sweets.

Excellent grades but poor behavior. Quick-witted and fond of mischief. He was the first in the class to deal damage to Koro-sensei.

A refreshing, athletic, and handsome popular guy. Ranked 2nd among the boys in knife skills.

Ranked 1st among the boys in knife skills. Handsome but not at all obnoxious. His lack of any obvious faults is, conversely, his weakness.