Small-time devil hunter Denji is trying to make a living in the world, until he dies on the job. Denji's devil dog, Pochita, merges with Denji's dead body and grants him the powers of a chainsaw devil. Now able to transform parts of his body into chainsaws, a revived Denji uses his new abilities to quickly and brutally dispatch his enemies. Catching the eye of the official devil hunters who arrive at the scene, he is offered work at the Public Safety Bureau as one of them. Now with the means to face even the toughest of enemies, Denji will stop at nothing to achieve his simple teenage dreams.