Denji's adolescent years were anything but typical as he was burdened with overwhelming debt from his deadbeat father. His sole companion was his fierce chainsaw devil pet, Pochita, with whom he hunted and slaughtered devils for the yakuza's profit. Despite his unfortunate circumstances, Denji longed for a peaceful existence with scrumptious meals and a lovely girlfriend by his side. But his aspirations were shattered when the treacherous yakuza orchestrated his cruel and premature demise, extinguishing any hope for future happiness. Miraculously, an ancient contract allowed Pochita to combine with Denji posthumously, endowing him with devil-like abilities that enabled him to transform his body parts into chainsaws. Given the considerable risk Denji's newfound powers posed to society, the esteemed devil hunter Makima of the Public Safety Bureau took him under her wing, granting him refuge on the grounds that he adhere to her every command. Driven by the prospect of a fulfilling life with an enticing woman, Denji poured all his energy into achieving his juvenile goals, vowing to fight for them with unwavering fervor.