Denji

The protagonist of the story. Self-proclaimed 16-year-old. A boy who works as an unofficial devil hunter alongside Pochita, the "Chainsaw Devil." He was living a life burdened with repaying the debt left by his deceased father, but when he was killed by yakuza who had contracted with the "Zombie Devil," Pochita became his heart and regenerated his body, granting him the ability to transform into the Chainsaw Devil. After slaughtering the Zombie Devil and the yakuza with that power, he is picked up by Makima and becomes a devil hunter affiliated with Public Safety.

He is a bold and fearless confident person, straightforward and simple-minded. He dislikes thinking deeply about things and is true to his desires, but these traits stem from his harsh childhood experiences and his longing for an ordinary life and happiness, "to live and die normally." Having known no other way of life than being a devil hunter since childhood, he lacks cooperation and common sense, but gradually shows growth by considering others and his way of life.

He holds affection for Makima, who was the first to treat him as a human being, and his primary goal is to continue missions at Public Safety and be acknowledged by her. Later, due to Makima's schemes, he transforms into "Chainsaw Man" and goes on a rampage, but with the help of Pochita and Power, he regains his form as Denji and confronts Makima again. Despite his affection for Makima never changing, he chooses to bear the sins together by consuming her body to completely kill her as an act of love, not attack, as a resolution for those who lost their lives due to her actions.

After everything ends, he lives with Nyako and the dogs left by Makima, but is entrusted with "Nayuta," the reincarnated Control Devil, by Kishibe and begins living with her. In the second part, "School Arc," he attends school as a high school student. While continuing to hunt devils, he hides the fact that he is Chainsaw Man, but internally wishes to reveal his identity to those around him.

Chainsaw Devil

Portrayed by: Masahide Tada, Yutaka Nakasone

Denji's transformed devil form. Red Chainsaw Man. By pulling the starter rope growing from his chest, he transforms. Upon transformation, his entire head takes on the shape of a chainsaw with sharp teeth, and guide bars and saw chains protrude from his arms, piercing through them. He uses human and devil blood as an energy source, and no matter how severe the injury, he can revive by pulling the starter rope on his chest, making him an immortal being. However, he has a weakness where he falls into a state of suspended animation if he becomes anemic and cannot regenerate his body.

In combat, he excels at violently slicing targets with the high-speed rotation of the blades protruding from various parts of his body, in addition to his superhuman physical abilities. Through numerous battles, he has also learned to control the blades protruding from his body, retract and extend them, and use extended chains for movement and restraint. It is later revealed that this form is temporary, and his true form is the hell hero "Chainsaw Man."

Chainsaw Man

Pochita's true form. When Denji's ego collapses, he transforms into this Chainsaw Man. Black Chainsaw Man. During transformation, something like intestines emerges from his abdomen and wraps around his neck like a scarf. He bears no resemblance to Denji and transforms into a more powerful and ferocious form than his usual transformation, with significantly amplified combat power. According to Makima, he is the "hell hero most feared by devils," appearing when devils call for help, but he is a chaotic being who kills all devils, including those who called for help, and continues to rampage, reviving no matter how many times he is killed. His exploits have earned him various emotions from devils, such as anger, fear, and reverence.

Another reason he is feared by devils is his ability to erase the existence of anything he eats, along with its name, from the world. The consumed existence is erased from all records and personal memories, resulting in the absence of things and concepts like "Nazis," "World War II," "AIDS," "nuclear weapons," and "sixth sense" in the world of the story.

He confronted Makima with overwhelming strength that allowed no one to approach, but as people began to see Chainsaw Man as a hero and stopped fearing him, he weakened and was defeated once. After weakening, his appearance resembles the previous Chainsaw Devil form with only armor added to his arms.