Kokushibo examines Muichiro Tokito in the See-Through world and recognises something in the boy, as Muichiro looks on at him. Thinking that Upper Moon One is quite dignified and majestic, Muichiro notices the blade at the Demon's side and wonders if he had been a Demon Slayer in the past.
Suddenly, Muichiro's hand starts shaking, with his sword hilt in its grip, unable to shake off a feeling of dread from being in front of Kokushibo. With his body refusing to battle, something that had never happened before in his entire life, Muichiro attempts to compose himself. Kokushibo asks him what his name is and Muichiro tells him with Kokushibo responding that the Tsugikuni name has died out.
Puzzled, Muichiro asks him who Tsugikuni is and Kokushibo continues and says that it was inevitable after so many centuries. The Upper Moon then tells Muichiro that when he had been human his name was Michikatsu Tsugikuni and then reveals that Muichiro is his descendant.
Muichiro's eyes widen in shock and he refuses to believe it at first, with his mind swimming with questions about the Upper Moon. Coming back to earth quickly, Muichiro steels himself and prepares to attack. Kokushibo praises his mental strength, lauding him for overcoming his panic in such a short time as Muichiro swoops forward and attacks him with a Mist Breathing: Second Form - Eight Layered Mist that the Demon effortlessly dodges in the blink of an eye.
Appearing behind Muichiro, Kokushibo praises the boy's Breath technique, seeing that his descendant was a Mist Breathing user and then swiftly dodges a Mist Breathing: Fifth Form - Sea of Clouds and Haze launched by the Mist Hashira. Accurately deducing Muichiro's age as being fourteen, Kokushibo is impressed that the boy's swordsmanship is so refined at his age and his mental fortitude to quell his fear and battle the Demon, taking pride in the strength still flowing through those of his blood.
Displeased, Muichiro rebuffs the Upper Moon, saying that if hundreds of years have indeed passed then not a drop of Kokushibo's blood remains in him. Muichiro activates his Demon Slayer Mark and performs a Mist Breathing: Seventh Form - Obscuring Clouds, a technique Kokushibo had never seen before. As Muichiro slices at the Demon's neck, Kokushibo quickly evades the attack, impressed with the beauty and grace of the attack.
Drawing his own blade, Kokushibo performs a Moon Breathing: First Form - Dark Moon - Evening Palace that Muichiro is unable to keep up with and the Hashira loses his left hand as a result. Shocked that the Upper Moon is able to use Breath techniques as a Demon, Muichiro quickly attempts to restrict the bleeding from the stump of his arm by tightening the sleeves of his robe with his teeth.
Dashing forward, Muichiro attacks Kokushibo despite his injuries and the Demon is impressed at the courage and skill of his descendant. As the Mist Hashira performs a Mist Breathing: Fourth Form - Shifting Flow Slash, Kokushibo catches the boy's blade between his fingers and turns it on him, pinning him to a pillar and then asks Muichiro to allow him to turn the Hashira into a Demon so that he could serve Muzan Kibutsuji.
Characters in Order of Appearance
- Kokushibo reveals the Muichiro is his descendant.
- Muichiro loses his left hand.