Denji, a young man who shares his life with Pochita, a chainsaw devil, is forced to survive by killing devils and selling their parts to pay off the debt he inherited after his father's death.
His existence has been a succession of hardships until a fatal betrayal leads to his death. In an unexpected turn, Pochita makes a pact with him, allowing him to resurrect as "Chainsaw Man", a hybrid entity with the heart of a demon.
This will cover the earlier parts of the Public Safety Saga, specifically from the Intro Arc to Eternity Devil Arc.