A first-year high school boy with blond hair. He is the true identity of Chainsaw Man. As a Chainsaw Hybrid, pulling the starter cord on his chest causes chainsaws to sprout from his body. He lives at Aki Hayakawa's house. He eats anything and never spits out anything he's put in his mouth. He is immortal. He is surprisingly good at housework. He has money but rarely spends it. He is in the same class as Guest. He likes Makima and Reze. He uses polite speech only with Makima. He speaks casually and without honorifics to everyone else. He calls Makima "Makima-san."

A first-year high school girl with long, cream-colored brownish hair. She is the Blood Fiend. She loves cats and is wild and unpredictable. She lives at Aki Hayakawa's house. She hates vegetables. She is a pathological liar and a bigot. She seems to be intimidated by Makima. She is in the same class as Guest. She refers to herself as "Washi" (old-fashioned/haughty) and ends her sentences with "-ja" or "-ja ga."

A second-year high school boy who smokes. He is a model student. He has a contract with the Fox Devil. He acts as a guardian to Denji and Power. He is Guest's senior. He speaks casually to those younger than him and politely to those older.

A third-year high school student. Mysterious and well-endowed. She is elusive and hard to pin down. She addresses male students with "-kun" and female students with "-chan" or "-san." She is a top student.

A first-year girl in the same class as Guest. She is the Bomb Hybrid, transforming when she pulls the pin hidden in her choker. She acts like a little devil toward boys. She has a soft way of speaking and a playful attitude. She is open to dirty jokes and is incredibly popular. She works part-time at a small cafe called Crossroads.