Bomb Girl arc

Spanning chapters 39 through 52 and adapted as the feature film Chainsaw Man, The Movie: Reze Arc, this story follows the Katana Man events and precedes the International Assassins chapter. It centers on Reze, an assassin posing as an ordinary girl, and uses her connection to Denji to explore his hunger for love and a normal life.

Fresh off beating the Katana Man, Denji again dreams of Pochita warning him never to open a certain door. He wakes to a punch from a blood-drunk Power, and Makima reassigns him alongside the Shark Fiend Beam before offering a date of her own. Their all-night movie marathon reveals a rare crack in Makima's composure, and she reassures Denji that he has a heartbeat. Soon after, a rainstorm pushes him into a phone booth where he meets Reze, charming her with a flower trick and accepting her invitation to the cafe where she works.

Over repeat visits the two grow close, and Reze takes Denji to a deserted school by night to teach him reading, math, and swimming. Unknown to him, a serial killer tied to the Typhoon Devil is stalking Reze to bait out Denji's heart, and Reze calmly strangles the attacker before returning to him without missing a beat. At a festival she confesses love and begs Denji to run away with her, but he refuses, wanting to keep his job. Her affection drops away instantly as she pulls the pin on her neck and transforms into her Bomb Hybrid form.

Beam snatches Denji to safety, and the chase reaches Division 2's headquarters, where Reze butchers the unit before Galgali and Kobeni slow her down. Denji recovers, transforms, and trades blows with her until Aki frees him from her grip. With the Typhoon Devil unleashed on the city, Denji devises a counter by riding Beam's shark form, and he finishes the swirling devil before luring Reze into the ocean, where her explosives are useless. They reminisce while drowning until Beam drags them ashore.

On the beach Reze admits her feelings were a deception, yet Denji still asks her to flee with him and promises to wait at the cafe at noon. Kishibe later tells Aki that Reze was raised as a Soviet experiment built to serve the state. Reze reconsiders and heads back toward Denji, but Makima, who had watched the whole courtship, intercepts and seemingly kills her with the Angel Devil's aid. A heartbroken Denji believes he was stood up, and the arc ends with him glumly devouring a bouquet in front of an irritated Power. Newcomers include Reze, the Typhoon Devil, the Mysterious Man, Nomo, Pig Devil, Kato, Tanabe, and Masaki Ando.