Aging Devil arc

Closing out the Academy Saga's penultimate slot, this is its fifth arc and, tallied from the start of the series, the thirteenth overall, covering Chapter 156 through Chapter 190. Denji, having defied Public Safety's orders and spent a week heavily sedated, is hauled into the Tokyo Devil Detention Center to be slowly taken apart. Takagi of Special Division 7 brags that the prison has never lost a devil and that any rescue would mean outright war.

The break-in is carried out by Yoru, Fami, and Asa Mitaka, though Yoru cannot shake her wish to fight Chainsaw Man the moment he appears. Asa's College Fund Turrets punch through the entrance defenses, and a pawn of Fami's, the Guillotine Devil, helps mow down the guards inside. That rescue also frees three captives, Seigi Akoku, Nobana Higashiyama, and Haruka Iseumi, who fall in with the group hoping to glimpse their hero. Takagi tries to halt the advance using the Nail Fiend alongside Katana Man, yet Asa flips both guards by telling them the prisoner they protect is really Chainsaw Man, and the two abandon Public Safety. Down on the third basement level the rescuers find their target already sawn into parts and packed into boxes. As they fit him back together, Haruka lifts out the head and exposes the shocking fact that the idol is Denji himself, leaving Asa reeling at the realization that Chainsaw Man and Denji are one and the same. Acting on Takagi's command, Quanxi assaults them but relents once she sees the severed head, and Takagi soon dies at the hands of his own Pseudo-Chainsaw wife. At Quanxi's request, Yoru ends the wounded veteran's life.

With Denji pieced back whole, everyone slips out and recuperates at Fami's place. Once conscious, Denji insists on locating Nayuta before granting anyone a rematch, only to find his home reduced to ash with no sign of her. Over cheap sushi, Barem Bridge claims to know where she is, then presents her decapitated head as a plate of food while boasting of his scheme to restore Pochita. Pushed past his limit, Denji rips the head clean from Barem as Pochita seizes control of the body and charges into battle.

Pochita rampages through Public Safety's divisions and wipes out the Ear Devil, but the agency strikes back by pairing the Octopus Devil that Yoshida commands with the Aging Devil, forcing the Chainsaw Devil to cough the Ear Devil back up and restore everyone's hearing. A courthouse revelation from Fumiko exposes a bargain to hand the Aging Devil ten thousand youths. Summoning the Tank and Gun Devils as gauntlets, Yoru regains her arms and tears into Pochita with her Gun Goddess, even crumbling the Statue of Liberty by spending the trigger fingers of the National Pistol Association's members. The Aging Devil then banishes the trio of Denji, Asa, and Yoru into a deathless, ageless realm. Inside it, Denji throws up the Snow and Bitterness Devils, his memories of Power, Aki, Nayuta, Reze, and his lost pets flooding back to rekindle his will to live. Feeding himself over and over to keep Pochita healing, he sustains the Chainsaw Devil against their immortal foe. Aided by Yoshida, Fumiko, the Octopus Devil, and one of the Aging Devil's own victims, the group cages the Primal Fear within its world and compels it to send the trapped humans home, afterward unwinding at a cafe as humanity wars with the Pseudo-Chainsaw People.