Denji, burdened by his late father's crushing debts, lives a grim life slaying devils alongside his only friend, the chainsaw devil Pochita. Betrayed and killed by the yakuza, Denji's dreams of happiness shatter. Miraculously revived by merging with Pochita, he gains chainsaw powers and becomes a hybrid. Taken in by Makima, a powerful Public Safety devil hunter, Denji must obediently fight dangerous threats, driven by his simple desire for a comfortable life and a loving relationship.