Chapter Summaries

Mu Yu explained the conditions and deadly cost of awakening Demon Slayer Marks and activating Scarlet Blades to Kyojuro, who resolved to use the knowledge against demons. After a Kasugai Crow summoned them northwest, Mu Yu and Kyojuro raced to their next mission.

• Mu Yu told Kyojuro that his sword Kanemoto was an Okatana rather than a Nichirin Blade and asked for help obtaining one.
• Mu Yu explained that Nichirin Blades could become Scarlet Blades, which hindered demons' regeneration, and Kyojuro realized the discovery could change the Demon Slayer Corps' fight.
• Mu Yu revealed that awakening Markings required a heart rate above 200 and a body temperature above 39 degrees, but marked swordsmen could not live past twenty-five.
• A Kasugai Crow called Mu Yu and Kyojuro to the northwest, and the two set off by racing each other.

Kyojuro Rengoku raced Mu Yu, then accepted his offer to learn a way to unlock his body's potential and fly with Geppo. They reached the battlefield where Upper Rank Two Douma had fought, and Mu Yu found Shinobu Kocho’s bloodstained butterfly ornament.

• Kyojuro Rengoku raced Mu Yu for an hour but could not keep up with his effortless pace.
• Kyojuro asked Mu Yu to become his tsuguko, then apologized and accepted Mu Yu’s offer to teach him a way to tap into his potential.
• Mu Yu used the Press-Press Fruit and Geppo to carry Kyojuro through the air toward the battlefield.
• Kyojuro agreed to learn Geppo after Mu Yu explained that Hashira might be physically capable of mastering it.
• Mu Yu and Kyojuro reached the battlefield and found shattered ice and bloodstains left from the fight with Douma.
• Mu Yu found Shinobu Kocho’s bloodstained butterfly ornament and grew concerned.

Mu Yu and Kyojuro Rengoku rushed toward Doma after finding Shinobu Kocho’s hairpin and evidence that several Hashira had fought the demon. They arrived to find Doma holding a woman’s arm, and Mu Yu unleashed his Conqueror’s Haki, making Doma feel fear and see memories of a warrior who had nearly defeated Muzan Kibutsuji.

• Mu Yu and Kyojuro found Shinobu Kocho’s abandoned butterfly hairpin and hurried after her.
• They discovered Tengen Uzui’s severed arm, then followed bloodstains and signs of Shinobu’s poison toward the battle.
• Mu Yu sensed Doma’s location, and he and Kyojuro reached the frozen lake where Tengen and Giyu Tomioka were fighting Doma’s ice puppets.
• Mu Yu saw Doma holding a woman’s arm and unleashed his purple-red Conqueror’s Haki, stopping the fighting.
• Doma felt fear for the first time and saw memories of a flame-marked warrior who had driven Muzan Kibutsuji into a desperate corner.

Mu Yu overwhelmed Doma and beheaded him, while the Hashira watched in disbelief. Doma’s head began to regenerate, but Shinobu Kocho arrived and injected more wisteria poison, destroying him for good.

• Doma attacked Mu Yu with a series of Blood Demon Arts, but none could reach or harm him.
• Mu Yu summoned the Myōō manifestation and shattered Doma’s Water Lily Bodhisattva, severing Doma’s neck.
• Shinobu Kocho ran up, and Mu Yu realized she had not been eaten by Doma.
• Doma tried to regenerate his head, but Shinobu Kocho stabbed him and injected more wisteria poison.
• Doma’s head exploded, and the Upper Rank Two demon turned to ashes.

After Mu Yu killed Doma, Shinobu Kocho struggled to process that she had avenged her sister, while the Hashira reconsidered their place beside Mu Yu. Mu Yu rescued Shinobu from the collapsing lake, and she saw her sister smiling at her in a rainbow, finally finding happiness in her revenge.

• Shinobu Kocho wondered whether she had truly killed Doma and felt hollow after achieving her long-held wish, while the Hashira were stunned by Mu Yu's strength.
• Kyojuro Rengoku resolved to follow Mu Yu and spread his techniques, Giyu Tomioka abandoned the idea of recruiting him as Water Hashira, and Tengen Uzui felt relieved enough to consider retirement.
• Mu Yu noticed Shinobu was distracted, warned her that the lake ice was collapsing, and carried her into the air with Geppo as the ice shattered.
• Shinobu realized Mu Yu was flying with her and awkwardly asked whether he was a demon who had saved her because she was a mermaid.
• Shinobu saw a rainbow above the collapsing lake and imagined her sister telling her to live happily; she cried while smiling.

Muzan gathered the Upper Rank demons and revealed that Mu Yu had killed Doma and Akaza, warning them that the human was a threat comparable to Tsugikuni Yoriichi. The demons learned how to respond if they encountered Mu Yu, and Muzan began explaining his abilities.

• Gyokko arrived in Infinity Castle and discovered that Doma and Akaza were missing, while Gyutaro, Daki, Hantengu, and Kokushibo were present.
• Nakime moved the Upper Ranks into a room, where Muzan confirmed that Doma and Akaza had died.
• Muzan said the same person had killed both demons without giving them a chance to fight back, and he and Kokushibo recalled Tsugikuni Yoriichi.
• Muzan showed the Upper Ranks Mu Yu's image and instructed them to flee if they met him alone, stall him in pairs, or surround him in groups of three.
• Muzan began explaining Mu Yu's abilities as the Upper Rank demons listened intently.

News that Mu Ye had easily killed Upper Rank Two Douma and Upper Rank Three Akaza spread through letters, filling the Demon Slayer Corps’ allies with disbelief and hope. Shinjuro, Jigoro, Sakonji, and Tamayo reacted to the news, while Zenitsu and Tanjiro were urged to train harder.

• Senjuro read Kyojuro’s letter and told Shinjuro that Mu Ye had killed two Upper Ranks, prompting Shinjuro to read the letter and weep with excitement.
• Jigoro learned that Mu Ye had slain Upper Rank demons and told Zenitsu that a new era was coming, then hauled him back into training when he tried to flee.
• Sakonji read the news and decided that Tanjiro needed to work even harder.
• Tamayo celebrated the deaths of Douma and Akaza, said she wanted to meet Mu Ye, and wondered how close his strength was to Yoriichi’s.
• Yushiro grew jealous when Tamayo spoke about meeting Mu Ye.

After the battle with Doma, Mu Yu healed Tengen Uzui’s injuries and severed arm with a Senzu Bean, persuading him to reconsider retirement. The Pillars sparred with Mu Yu and tested his techniques, leaving them impressed by his strength and extraordinary talent.

• Shinobu Kocho treated the Pillars’ injuries, while Tengen Uzui announced that he planned to retire and spend time with his three wives.
• Mu Yu gave Tengen Uzui a Senzu Bean, which healed his injuries and regrew his severed arm.
• Mu Yu teased Tengen Uzui about retiring with his wives, making Shinobu Kocho and Giyu Tomioka laugh and easing the mood.
• Mu Yu explained Soru to the Pillars and demonstrated his flying techniques, prompting them to experiment and master Soru, though none could grasp Haki.
• Mu Yu learned Giyu Tomioka’s Water Breathing: Eleventh Form: Dead Calm and practiced Flame, Sound, and Insect Breathing, leaving the Pillars awed by his talent.

Mu Yu arrived at Demon Slayer Corps Headquarters for a Hashira meeting and faced Sanemi Shinazugawa’s hostility. After Mu Yu dodged Sanemi’s attack with [Soru], he stopped Sanemi’s nearly full-strength sword strike with one finger, leaving the Hashira stunned.

• Mu Yu entered the headquarters courtyard with several Hashira, where the assembled Kakushi wondered why the Hashira treated him with such respect.
• Sanemi Shinazugawa challenged Mu Yu, while Shinobu Kocho, Kyojuro, and Tengen Uzui defended him.
• Sanemi drew his Nichirin Blade and accused Mu Yu of hiding behind women, prompting Shinobu and Mitsuri Kanroji to object.
• Mu Yu used [Soru] to appear behind Sanemi and criticized his low emotional intelligence.
• Sanemi spun around and slashed at Mu Yu, but Mu Yu blocked the strike with one finger, astonishing every Hashira.

Mu Yu demonstrated Armament Haki to the Hashira, then asked them to accept Nezuko as a demon who did not eat people. Their disagreement nearly turned into a fight before Kagaya Ubuyashiki arrived, and Mu Yu noticed how severely ill he was.

• Mu Yu blocked Sanemi Shinazugawa’s sword and Wind Breathing attack with Armament Haki, impressing the Hashira.
• Mu Yu told the Hashira that Nezuko was Tanjiro Kamado’s younger sister and did not eat people.
• Gyomei Himejima, Iguor Obanai, Muichiro Tokito, Kyojuro Rengoku, Tengen Uzui, and Sanemi Shinazugawa rejected Mu Yu’s request without proof.
• Sanemi Shinazugawa, Iguor Obanai, Gyomei Himejima, and Muichiro Tokito surrounded Mu Yu as tensions escalated.
• Two girls announced Kagaya Ubuyashiki’s arrival, and the Hashira knelt as he entered the courtyard.
• Mu Yu sensed that Kagaya Ubuyashiki was gravely ill and saw that the sickness had eroded half his face.

Mu Yu urged Kagaya Ubuyashiki and the Hashira to investigate Nezuko before judging her, and Kagaya revealed that the Corps already worked with Tamayo, a demon who did not eat people. Tamayo’s restraint convinced the Hashira, and Sanemi Shinazugawa apologized after testing her with his Rare Blood.

• Mu Yu asked the Hashira to investigate Nezuko carefully, and Kagaya Ubuyashiki promised the Corps would not make things difficult for her if the claims were true.
• Kagaya Ubuyashiki revealed that the Corps knew two demons who did not eat people and summoned Tamayo to demonstrate.
• Tamayo explained that she survived on small amounts of blood bought from willing donors.
• Sanemi Shinazugawa exposed his Rare Blood and challenged Tamayo, but she resisted the temptation.
• Kagaya Ubuyashiki told Sanemi Shinazugawa to sheathe his sword and apologize, and Sanemi bowed to Tamayo.

Tamayo warned Mu Yu and the Hashira that Muzan was extraordinarily difficult to kill, but Kagaya rallied them to prepare together. Mu Yu then challenged all nine Hashira to fight him at once.

• Mu Yu learned that Nezuko had been spared Sanemi Shinazugawa's attack and received three million energy points.
• Tamayo asked whether Mu Yu had innate Markings, then explained that Muzan had survived being cut into more than 1,500 pieces by Tsugikuni Yoriichi.
• Tamayo warned that Muzan would use cowardly tactics and might split into 3,000 or more fragments to escape.
• Kagaya encouraged the Hashira to rely on teamwork, while Kyojuro Rengoku and Shinobu Kocho offered to use Tamayo's knowledge to help defeat Muzan.
• Tamayo offered to work with Shinobu on a medicine that could turn Muzan back into a human.
• Mu Yu challenged all nine Hashira to fight him at once, stunning Tamayo.

Mu Ye demonstrated his overwhelming speed and swordsmanship against Sanemi Shinazugawa, then faced the Hashira’s coordinated attack. The chapter ended with Mu Ye using an improved Dead Calm to stop their assault.

• Sanemi Shinazugawa attacked Mu Ye with Wind Breathing, but Mu Ye appeared behind him and cut three openings in his clothes without harming him.
• Mu Ye told the Hashira that he had used an Iaijutsu technique capable of three slashes in one second, then challenged them to attack together.
• Gyomei Himejima struck Mu Ye with his axe and Meteor Hammer, but Mu Ye knocked both weapons back with Kanemoto.
• The Hashira coordinated attacks from every direction, and Mu Ye countered with his improved Water Breathing, Eleventh Form: Dead Calm, leaving everyone frozen in their attacking stances.

Mu Yu faced the Nine Hashira in a fierce sword battle, overpowering their attacks while enjoying the clash of their techniques. As the Hashira pressed him to use the move that had killed Doma, Mu Yu revealed a second blade and announced that he was a Two-Sword Style swordsman.

• Mu Yu dismissed the Nine Hashira's strength after blocking their combined attacks, provoking them to fight him in earnest.
• Sanemi Shinazugawa, Muichiro Tokito, Mitsuri Kanroji, and Iguor Obanai attacked Mu Yu with their Breathing techniques, but he countered them and swept several into the air with Water Breathing: Sixth Form: Twisting Whirlpool.
• The Hashira continued attacking with their varied techniques as Mu Yu savored the quality of the sword battle and came to understand Hawk Eyes' respect for Zoro.
• Sanemi Shinazugawa and Kyojuro Rengoku challenged Mu Yu to use the move he had used to kill Doma.
• Mu Yu summoned Myōō, revealed his second sword, and announced that he was a Two-Sword Style swordsman.

Mu Yu defeated the Nine Hashira with a precise sword technique and offered to teach them Haki, earning their respect. After the system rewarded him with a method for condensing Haki Seeds, Mu Yu offered the shortcut, and Shinobu Kocho volunteered to try it.

• Mu Yu challenged the Nine Hashira’s resolve, and they charged him again despite his claim that he had used only a fraction of his strength.
• Mu Yu unleashed his Fifth Stance, Garden of the Gods, and engulfed the Hashira in a sea of cherry blossom blades that pierced their clothes without injuring them.
• The Hashira accepted their defeat, and Mu Yu offered to teach them Haki; Kyojuro Rengoku revealed that Mu Yu had already taught him and the others its cultivation method.
• The system rewarded Mu Yu with energy points and the method for condensing Haki Seeds, granting him half of the Haki cultivated by anyone he taught.
• Mu Yu offered to implant Haki Seeds as a shortcut, and Shinobu Kocho stepped forward to volunteer.

Mu Yu spent a relaxing day at Butterfly Mansion with Mitsuri Kanroji, who rushed over in tears because she had slept through lunch. They hunted and ate together, and the chapter ended with Mitsuri asking Mu Yu to claim they had stolen honey to nourish her brain after she supposedly practiced Sword Kata.

• Mu Yu relaxed in the sunlight at Butterfly Mansion, where his Photosynthesis skill stored more energy and strengthened him.
• Mitsuri Kanroji ran to Mu Yu crying because Shinobu had not woken her for lunch after she fell asleep following her bath.
• Mu Yu agreed to find food with Mitsuri, and they ate honey and a roasted rabbit together.
• Mitsuri asked Mu Yu why his swordsmanship and Haki were so impressive, and he let her believe he trained through constant contemplation.
• Mitsuri asked Mu Yu to tell Shinobu that she had stolen honey because she needed nourishment after thinking about Sword Kata.

Mu Yu helped Mitsuri Kanroji think about creating Love Breathing’s Seventh Form, then began developing a Breathing Technique suited to himself. When Mitsuri woke and saw him practicing with her Nichirin Blade, she recognized his sword technique as the inspiration for her new form.

• Mitsuri Kanroji asked Mu Yu to help her create Love Breathing’s Seventh Form, explaining that her failed arranged dates gave her no experience to draw on.
• Mu Yu suggested romance stories, kabuki, and her parents as possible inspiration, but Mitsuri rejected them as unsuitable.
• While Mitsuri slept, Mu Yu considered combining the strengths of different Breathing Techniques into one suited to his powerful physique and decided to visit Mt. Sagiri after his Nichirin Blade was forged.
• Mitsuri woke after sunset and saw Mu Yu practicing with her whip-like Nichirin Blade, whose circling movements grew faster and more agile.
• Mitsuri Kanroji recognized Mu Yu’s sword technique as the inspiration for her Love Breathing Seventh Form.

Mu Yu helped Mitsuri Kanroji create the Seventh Form of Love Breathing, prompting Shinobu Kocho to tease them about their afternoon together. The next day, Shinobu asked Mu Yu to help her develop a new Insect Breathing dance.

• Mu Yu demonstrated a swift sword technique that inspired Mitsuri to ask him to create the Seventh Form of Love Breathing for her.
• Mitsuri told Shinobu that Mu Yu had helped her, grilled meat for her, and made her feel overwhelmed by the new form, while Mu Yu tried to explain.
• Shinobu decided Mitsuri would get no dinner after eating grilled meat, leaving Mitsuri confused and hungry.
• The next day, Shinobu demonstrated her Butterfly Dance - Trickery and asked Mu Yu to help her create a new Insect Breathing dance.

Mu Yu created a new Insect Breathing technique for Shinobu, refining it into three linked sword forms. Shinobu pretended she could not learn it to tease him, then admitted she had mastered it and offered to cook for him.

• Mu Yu studied Insect Breathing and devised Firefly Dance, a rapid series of thrusts that concentrated Shinobu’s stamina into a single attack.
• Shinobu watched Mu Yu demonstrate Firefly Dance but said she could not see the movements clearly, so he explained and taught it to her.
• When Shinobu claimed she still had not learned the technique, Mu Yu divided it into Firefly Flash, Firefly, and Lamp Talk, redesigning them as linked forms with up to fifteen consecutive thrusts.
• Shinobu admitted she had been teasing Mu Yu and had learned the technique earlier, then offered to cook for him.
• Mu Yu asked for everything she was good at making, and Shinobu jokingly called him cruel.

Mu Yu reflected on the worsening casualties among the Demon Slayer Corps while staying at the Butterfly Mansion and continuing to train its members. Tetsukoma delivered Mu Yu’s newly forged green Nichirin Blade, which Mu Yu provisionally named Muzankiri and hoped to use to kill Muzan Kibutsuji.

• Mu Yu watched the growing number of wounded Corps members arrive at the Butterfly Mansion and continued teaching them swordsmanship and Breathing Techniques.
• Shinobu Kocho praised Mu Yu’s instruction in Firefly Dance and offered to make him dinner.
• Tetsukoma arrived at the Butterfly Mansion with Mu Yu’s newly forged Nichirin Blade, marked with the words “Demon Slayer.”
• Mu Yu’s blade turned green, and he named it Muzankiri, though Tetsukoma kept adding his own name to it.
• Mu Yu said he would settle the blade’s name after using it to cut off Muzan Kibutsuji’s head.