Kokushibo stands in front of Muichiro Tokito after having pinned him to a pillar with his own blade and says that his heart is moved on seeing one of his own descendants, something he had never imagined. Muichiro stares at the Upper Rank in silence as Kokushibo continues and says that the Mist Hashira's arm would regrow once he became a Demon, certain that Muzan Kibutsuji would allow such a thing, given that the other Upper Ranks had all been slain.
Transfixed on his descendant, Kokushibo attempts to try and stem Muichiro's bleeding but then says that if Muichiro died due to excessive blood loss or if he were rejected by Muzan then it would be fate. Kokushibo tells Muichiro that this would mean he was a man only meant to go so far as Genya Shinazugawa attempts to sneak up on the Demon from afar behind one of the pillars. As Genya shoots at him, he is left utterly shocked as Kokushibo instantly appears behind him and asks if he agrees with his statement and slicing off Genya's gun arm so fast he wasn't even able to notice.
As Genya's left arm plops to the ground the boy looks in shock and attempts to defend himself as Muichiro is horrified and yells out to Genya. Before his hand is able to fully draw his blade, Kokushibo swiftly slices off his other arm as well, leaving the boy bleeding profusely. He sees that Genya has been eating Demons and slices his torso clean in half.
Muichiro is horrified at the sight and attempts to pull his blade out of himself but in vain as he is unable to make it budge. Kokushibo is surprised that Genya is still alive despite having his torso cut in half and tells him that around three hundred years ago there was another swordsman who ate Demons just like he did. Saying that he had killed that particular swordsman by slicing his torso in half, Kokushibo says that if the same strategy did not work on Genya then perhaps the boy's weak point was be his head.
Genya tries to crawl towards his arms to attempt to reattach them as Kokushibo says that he has no reason to allow a fake demon like him to live and begins to slice at his head. Suddenly, he is intercepted by Sanemi Shinazugawa performing a Wind Breathing: Fourth Form - Rising Dust Storm as Genya is left shocked. Kokushibo immediately retreats backwards and recognises Sanemi as the Wind Hashira as the latter says he is the wind that will rip Kokushibo's head off.
Genya whispers to his brother who roughly responds by calling Genya a pathetic little brother, telling him that the reason he went so far as to kill their own mother was that he wanted to protect Genya. Flashing back to a conversation he had with Tanjiro Kamado during Hashira Training, Genya remembers that Tanjiro told him he could not smell a tinge of hatred in Sanemi towards Genya and Tanjiro had told him he did not need to be afraid of his brother because Sanemi had loved him all the while.
Sanemi continues and tells Genya that he should have lived a normal life until he reached a ripe old age and attempted to make his wife and children happy, in return for all the happiness that had been taken from them, their siblings and their mother. As Sanemi tells him that he would not have let a single Demon get near Genya no matter what, Genya tears up and apologises to his brother.
Meanwhile, Kokushibo feels nostalgic upon seeing a pair of Demon Slayer brothers. Enraged, Sanemi curses at Kokushibo and lunges forward to attack, as Kokushibo slices at him. Ducking and sliding between Kokushibo's legs, Sanemi catches the Demon's foot and flips him over, launching a Wind Breathing: First Form - Dust Whirlwind Cutter at the Upper Rank without pause. Sanemi matches blades with Kokushibo, who finally draws his sword out for all to see, a grotesque blade with eyes and veins running down the side of it's length as Sanemi notes how disgusting the sight is.
Characters in Order of Appearance
- Genya is sliced in half.
- Sanemi joins the battle.