Hirasawa is the 42nd chapter Ajin: Demi-Human, created by Gamon Sakurai.
After reaching the top floor, Nakano shoots at the door in an attempt to open it but to no success. Kei explains that they need create holes in certain parts of the door to open it. Kei explains that in order to create the holes, they need to cut off his arms. Hearing this, Hirasawa gets out a large knife.
Kei explains that Sato opened the door by first chopping of his arm and dumping outside the range where it would reattach. Afterwards, Sato would go back a kill himself and puts his wound against the door which would break down the obstacles that is in the way of his regeneration. Kei compares this event to when Nakano is shot but the bullet disappears when he recovers and that the unknown substance produced is breaking down the obstacles similar to when a body breaks down alcohol. After Kei's explanation, Nakano and Hirasawa prepares to chops Kei's arms off.
Meanwhile, Sato is still looking for Kei on the 15th floor when he sees an arm fall down the stairs and quickly realises that he is still on the roof.
After reaching the roof, Hirasawa informs Kei and Nakano that they are running so that they can regroup and try again later. Nakano looks down noting how high up they were. Nakano questions how Hirasawa is going to get down and Hirasawa informs him that he is going to use a cleaning lift but Kei notices that there is something wrong with Hirasawa's top. Due to the wind, Nakano accidentally falls off the building.
Kei points out that there isn't any cleaning lifts and questions why Hirasawa's top button is done up, Hirasawa confesses that he has been shot and that he is going to die. Hirasawa gives Kei his gun telling him that he doesn't need it. Sato then arrives asking if Kei is going to run. Hirasawa tells Kei that he should run from the entire battle and there is nothing obligating him to fight but Kei refuses and takes out a tranquilliser gun preparing to fight Sato. Hirasawa looks at Kei telling him that he had fun and it felt like he was watching his own sons before shooting him off the building.
After seeing Kei fall off the building, Sato gives up trying to decapitate Kei and prepares to fight Hirasawa in hand to hand combat. After falling off Kei summons his IBM in an attempt to get back up but the IBM ignores him and lets him fall off to his death. Kei's IBM scales the building and sees a beat up Sato standing next to Hirasawa's dead body commenting on Hirasawa's toughness. Kei's IBM attempts to attack Sato but Sato jumped off the building telling Kei that they'll meet again at the final wave.