Chapter Summaries

Su Chen headed to Kanamori's forge to find Tanjiro and learn Sun Breathing and Water Breathing. Meanwhile, Kokushibo learned that Su Chen had gone to the Swordsmith Village and set out with the Shadow Demon to track him down.

• Shinobu Kocho and Kanao Tsuyuri left Su Chen with the Nichirin Blades he had given them, and he went to Kanamori's forge to look for Tanjiro.
• The Shadow Demon told Kokushibo that Su Chen had been at the Butterfly Mansion, then revealed Luo Chuan had reported that Su Chen was in the Swordsmith Village.
• Kokushibo severed the Shadow Demon's hands for bringing incomplete information, but spared it after it explained how its Blood Tracking ability could locate Luo Chuan's accomplice.
• Kokushibo asked Nakime to send him out, and the Shadow Demon used its planted shadow in Luo Chuan to give her a destination.
• Nakime teleported Kokushibo and the Shadow Demon, then angrily strummed her instrument to jolt them during their journey.

Kaigaku watched Su Chen at the Swordsmith Village hot springs so he could report his whereabouts to Luo Chuan, while Su Chen used the time alone to study Tanjiro’s Breathing Styles. Su Chen mastered Water Breathing and then began comprehending Sun Breathing.

• Nakime laughed over her scheme until a familiar voice made her realize the boss had caught her.
• Kaigaku hid near the men’s hot spring, spotted Su Chen, and left to report his whereabouts to Luo Chuan.
• Su Chen sensed that someone had been watching him and waited until they left before entering meditation.
• Su Chen recalled Tanjiro demonstrating Water Breathing and Sun Breathing at Kanamori’s forge.
• Su Chen used his Memory Palace to comprehend Water Breathing and memorize all ten forms.

Su Chen mastered Sun Breathing’s forms, including the Thirteenth Form, while its power transformed the White Dragon in his Memory Palace into a Sun Dragon. As he relaxed in a Swordsmith Village hot spring, his Perception Compass suddenly detected someone nearby.

• Su Chen repeatedly simulated Sun Breathing’s forms until he had grasped them, then linked the First through Twelfth Forms into the Thirteenth Form.
• Sun Breathing transformed the White Dragon in Su Chen’s Memory Palace into a Sun Dragon whose heat overwhelmed the neighboring dragons and whose domain crossed theirs.
• Su Chen ordered the Sun Dragon to keep peace among the dragons before leaving the Memory Palace.
• At the Swordsmith Village hot spring, Su Chen finished practicing the Thirteenth Form in his mind.
• Su Chen sensed someone nearby, and his Perception Compass began jumping wildly.

Muichiro Tokito waited all day for Kanamori to give him a replacement Nichirin Blade, and Kanamori offered to forge him a better one after realizing he had kept him waiting. Tokito refused until Kanamori mentioned Su Chen’s alloy technique, then agreed to try an alloy blade because he trusted Su Chen.

• Kanamori found the pale blue Nichirin Blade he had forged for Tokito and handed it over.
• Tokito praised the blade and said he would return when it broke, leaving Kanamori dissatisfied with his own craftsmanship.
• Kanamori offered to forge Tokito another blade to make up for the long wait, but Tokito repeatedly refused.
• Kanamori told Tokito he had learned Su Chen’s alloy technique and could forge a blade with it.
• Tokito agreed to an alloy blade, explaining that he trusted Su Chen not to lie.

Muichiro Tokito encountered a demon on his way back from arranging for Kanamori to forge him a Nichirin Blade, then faced Kokushibo, Upper Rank One. As Tokito prepared a surprise attack, Kokushibo read his movements and identified his Mist Breathing technique.

• Kanamori and Muichiro Tokito agreed that Tokito would collect a newly forged Nichirin Blade in two weeks.
• Tokito traveled through the dark Swordsmith Village and noticed a demon hiding near the hot springs.
• Tokito quickly drew his Nichirin Blade and nearly killed the demon before it called for an Upper Rank.
• Kokushibo appeared behind Tokito, and his overwhelming presence made Tokito tremble with fear.
• Tokito steadied himself with Total Concentration and prepared a surprise Mist Breathing attack, but Kokushibo calmly described the technique and its target.

Muichiro Tokito fought Kokushibo, who revealed that he was Tokito’s ancestor and tried to persuade him to become a demon. After Kokushibo’s face developed a Demon Slayer Mark, he set Tokito down and walked toward the hot springs, leaving Tokito hurt and wondering who he intended to confront.

• Kokushibo outmaneuvered Tokito, slammed him against a tree, and severed his thumb.
• Kokushibo killed the shadow demon after it urged him to kill Tokito.
• Kokushibo told Tokito that he was his ancestor and that the Tsugikuni bloodline ran through Tokito’s veins.
• Kokushibo bound Tokito’s severed thumb back onto his hand and invited him to become a demon.
• Kokushibo’s face developed a Demon Slayer Mark, and he lowered Tokito to the ground before walking toward the hot springs.

Kokushibo entered the hot spring to confront Su Chen, while Kaigaku hid nearby and stole Kokushibo’s Nichirin Blade. Su Chen revealed that he knew Kokushibo’s human identity, provoking a tense response.

• Tokito left immediately to protect the Swordsmith Village’s people and resources, while Kokushibo continued toward the hot spring.
• Kokushibo entered the hot spring after Su Chen invited him to talk, and Kaigaku emerged from hiding outside.
• Kaigaku decided to wait for a chance to attack, then slipped into the changing room and stole Kokushibo’s Nichirin Blade.
• Su Chen identified Kokushibo as Upper Rank One and named him as Yoriichi Tsugikuni’s older brother, Tsugikuni Michikatsu.
• Kokushibo reacted angrily to hearing Yoriichi’s name and warned Su Chen that he would make his suffering brief.

Su Chen refused Kokushibo’s offer to become a demon and faced him in battle, narrowly dodging Kokushibo’s opening strike. After studying Kokushibo’s Flesh Blade, Su Chen used his blood and bodily control to forge a similar blade, revealing himself as a Demon Eater and astonishing Kokushibo.

• Su Chen refused Kokushibo’s invitation to become a demon and agreed to fight him.
• Kokushibo drew a Flesh Blade from his arm and attacked with Moon Breathing, First Form: Dark Moon, Evening Palace.
• Su Chen activated his Time Domain and dodged Kokushibo’s opening slash, though the demon’s speed shocked him.
• Su Chen recalled how Kokushibo formed his blade, then used his blood and bodily control to forge a blade of his own.
• Kokushibo recognized Su Chen as a Demon Eater and was stunned that he had copied the Flesh Blade so quickly.

Su Chen countered Kokushibo’s Blood Demon Art and Moon Breathing attacks, then wounded him with a Moon Breathing strike combined with Wind Dragon Form. Kokushibo grew excited by the challenge and tried to identify the Breathing Style behind Su Chen’s next move.

• Kokushibo transformed his Flesh Blade with Blood Demon Art: Demonic Blade Transformation and challenged Su Chen to imitate it.
• Kokushibo attacked with Moon Breathing’s First and Second Forms, but Su Chen blocked the scattered crescent blades and deflected the main slashes with his own transforming blade.
• Su Chen countered with Moon Breathing, First Form: Dark Moon: Evening Palace, then used Wind Dragon Form, First Form: Wind Roaming, Heavenly Soar to cut Kokushibo beneath his left arm.
• Kokushibo was stunned to find himself wounded, then became excited by Su Chen’s strength.
• Su Chen prepared another attack while Kokushibo tried to guess which Breathing Style it used.

Su Chen used Sun Breathing to defeat Kokushibo’s attack, forcing Kokushibo to confront his fear of Yoriichi Tsugikuni and withdraw. Exhausted from forging a Flesh Blade with his blood, Su Chen sensed another nearby presence whose strength seemed manageable.

• Kokushibo recognized Su Chen’s technique as Sun Breathing and remembered his jealousy of Yoriichi Tsugikuni and his inability to master the style.
• Su Chen and Kokushibo clashed with Sun Breathing’s Dance and Moon Breathing’s First Form, Dark Moon: Evening Palace.
• Kokushibo’s fear resurfaced during the clash, and his Moon Breathing collapsed before Su Chen’s attack; he admitted defeat and left.
• Su Chen dismissed the Flesh Blade and realized that forging it and fighting had nearly depleted his blood energy.
• Su Chen detected someone nearby with his Perception Compass and judged that the presence was not very strong.

Su Chen received a letter from Akaza through Chachamaru, while Akaza stayed with Tamayo and Yushiro and agreed to follow Tamayo’s rules. Elsewhere, Kokushibo found Kaigaku impaled on the transformed Flesh Blade and realized he was still alive.

• Chachamaru delivered Akaza’s letter to Su Chen, who learned Akaza had found Tamayo and persuaded her to help with their request.
• Akaza told Tamayo and Yushiro he had escaped Muzan’s control, and Tamayo warned him not to feed on humans or use violence.
• Kokushibo brooded over Su Chen’s Sun Breathing and his own inability to defeat it with Moon Breathing.
• Kokushibo discovered Kaigaku impaled by the Flesh Blade he had left behind and noticed that Kaigaku was still breathing.

Kokushibo turned the dying Kaigaku into a demon, and Kaigaku attacked him before Kokushibo left. Kaigaku then hunted Kotetsu through the Swordsmith Village until Mitsuri Kanroji intervened, and she asked Kotetsu what had happened.

• Kokushibo gave Kaigaku his blood, and Kaigaku’s wounds healed as he transformed into a demon.
• Kaigaku attacked Kokushibo, who disarmed him and judged him strong enough to become Upper Rank Six before leaving on Muzan’s summons.
• Kaigaku followed the scent of Kotetsu, who tried to evade him through the Swordsmith Village until Kaigaku cut down a tree with a Thunder Breathing attack.
• Mitsuri Kanroji blocked Kaigaku and severed his blade, but Kaigaku escaped as sunlight reached him.
• Mitsuri checked that Kotetsu was safe and asked him what had happened in the Swordsmith Village.

After Kokushibo’s attack, Su Chen examined the badly injured Muichiro Tokito and discovered that he had fractures, severe wounds, and poison from an Upper Rank’s blade. Tokito needed treatment and the recovery of his lost memories to wake up, leaving Su Chen and the others facing a critical, uncertain chance to save him.

• Shinobu Kocho, Kanao Tsuyuri, Muichiro Tokito, and Kanamori gathered with Su Chen to discuss Kokushibo’s attack, while Tokito coughed up blood.
• Tokito tried to insist he was fine, then collapsed unconscious, and Shinobu Kocho found that his injuries were too severe for her to assess fully.
• Su Chen examined Tokito with the Time Domain and found multiple fractures, swollen injuries, and signs that he was unconscious.
• Su Chen told Shinobu Kocho that Tokito had been poisoned by Kokushibo’s blade, and she agreed to neutralize the toxin.
• Su Chen warned Kanamori that Tokito’s mental block and severe memory loss had to be overcome for him to wake, and that he might have only one chance.

After Upper Rank One attacked the Swordsmith Village and Tokito fell into a coma, Kagaya Ubuyashiki made a grave plan and called an urgent Hashira Meeting. The meeting revealed Su Chen's fight with Upper Rank One and ended with the Stone Hashira affirming that the Corps would protect Su Chen.

• Su Chen sent Tokito to the Butterfly Mansion and asked Shinobu Kocho to contact him when Tokito woke.
• Kagaya Ubuyashiki heard Lady Amane's report about Upper Rank One and Tokito, then whispered a plan that alarmed her because it would cost him his life.
• Kagaya Ubuyashiki called an urgent Hashira Meeting attended by the Stone Hashira, Giyu Tomioka, Mitsuri Kanroji, and Su Chen.
• Lady Amane recounted the Swordsmith Village attack, and Su Chen said he had fought Upper Rank One before the demon escaped.
• The Stone Hashira praised Su Chen's role in the Corps and said the Demon Slayer Corps would mobilize to protect him if he were in danger.

At a Hashira meeting, Lady Amane revealed that Luo Chuan had leaked information that led to Kokushibo’s attack on the Swordsmith Village, then announced that Hashira Training would begin in a week. After the meeting, she asked Su Chen to examine Kagaya Ubuyashiki, whose illness had become extremely serious.

• Lady Amane told the Hashira that Kaigaku had become a demon and that the Corps had uncovered Luo Chuan as a spy who may have exposed the Swordsmith Village.
• The Stone Hashira and Giyu thanked Su Chen for helping defend the Swordsmith Village, and Su Chen credited Tokito for standing against Kokushibo.
• Su Chen warned that the demons would make a major move, and Lady Amane announced that Hashira Joint Training would start in one week.
• Lady Amane asked Su Chen to examine Kagaya Ubuyashiki, explaining that his illness was severe and that previous doctors had been unable to help.

Su Chen examined Kagaya Ubuyashiki and discovered that his body was being ravaged by a mysterious curse-like illness. Believing he might help by awakening Kagaya’s Demon Slayer Mark, Su Chen began channeling his fighting spirit into him, leaving Lady Amane astonished by his promise that he could do something.

• Su Chen went with Lady Amane to examine the gravely ill Kagaya Ubuyashiki.
• Su Chen used the Transparent World to detect widespread organ failure and rapidly deteriorating, mutated cells in Kagaya’s body.
• Su Chen suspected the illness was connected to Muzan and considered whether it resembled cancer or the effects of the Demon Slayer Mark.
• Su Chen decided to try awakening Kagaya’s Demon Slayer Mark by channeling his fighting spirit and vitality into him.
• Su Chen warned Kagaya that the attempt might hurt but could give him a way to help, and Lady Amane reacted in astonishment.

Su Chen prepared to treat Kagaya Ubuyashiki’s curse by channeling fighting spirit into his failing body, warning Kagaya and Amane Ubuyashiki that the process could be fatal. As he began, Su Chen used his abilities to perceive Kagaya’s faint life line and realized he could not delay.

• Su Chen assured Kagaya Ubuyashiki and Amane Ubuyashiki that he had a treatment method, but warned that it was dangerous.
• Kagaya Ubuyashiki and Amane agreed to proceed, and Amane told Su Chen she would not blame him if he failed.
• Su Chen placed both hands over Kagaya Ubuyashiki’s heart and focused on their heartbeats.
• Su Chen activated time domain and Clairaudience, entered his memory palace’s core, and saw Kagaya Ubuyashiki’s dangerously weak life line.
• As the life line weakened further, Su Chen stopped waiting, and his hands began to move.

Su Chen used Fighting Spirit to strengthen Kagaya Ubuyashiki’s heart, and Kagaya felt warmth, easier breathing, and the return of some sensations. Su Chen judged that the heart had recovered enough to withstand a stronger treatment and prepared to begin the next stage.

• Su Chen infused Fighting Spirit into Kagaya Ubuyashiki’s heart to improve its strength and blood circulation.
• Kagaya cried out from the treatment’s intense comfort, and Amane feared he was in pain.
• Kagaya reassured Amane that he felt comfortable and noticed that his breathing and sense of taste had improved.
• Amane believed Kagaya and moved behind them so she would not disturb the treatment.
• Su Chen saw that Kagaya’s heart had recovered enough and prepared to increase the Fighting Spirit for the next stage.

Su Chen pushed Kagaya Ubuyashiki through the first two stages of his treatment, forcing Fighting Spirit through his body as Kagaya endured excruciating pain and lost consciousness. Su Chen prepared to begin the final, life-or-death stage of awakening Kagaya’s Demon Slayer Mark.

• Su Chen began circulating Fighting Spirit through Kagaya Ubuyashiki’s heart and blood to purify it and restore his internal organs.
• Kagaya screamed and suffered unbearable pain as the Fighting Spirit spread through his body, while Lady Amane mistook his distress for a sign that the treatment was working.
• Kagaya hallucinated a brutal memory of his mother beating him, then fell unconscious; Lady Amane believed he had peacefully fallen asleep.
• Su Chen watched Kagaya’s wildly fluctuating lifeline in the Memory Palace and completed the second stage of treatment.
• Su Chen began breathing with Total Concentration and raised both hands to inject Fighting Spirit for the final stage, leaving Kagaya’s survival to his willpower and body.

Kagaya Ubuyashiki awoke from a dream of his mother after Su Chen activated his Demon Slayer Mark. Though his body remained weak, he could move and stand again, leaving Lady Amane and Kagaya overwhelmed with joy.

• Kagaya Ubuyashiki dreamed that he had returned to childhood, spoke with his mother, and resolved to keep leading the Demon Slayer Corps despite his pain.
• Kagaya's body manifested black marks and wisteria blossoms as he began to awaken from the dream.
• Kagaya woke in his room beside Lady Amane, and Su Chen told him that he had activated Kagaya's Demon Slayer Mark.
• Kagaya discovered that he could move, then stood with Lady Amane's help and celebrated his regained strength.