Chapter Summaries

Oboro was brought to Qinglin Town’s shrine and witnessed villagers trading captives to a demon for money. Inside, he discovered the demon was Upper Rank Five and offered it his soul, leaving the demon curious and hostile.

• The old man and the maid brought Oboro to a shrine ritual where villagers offered unconscious outsiders to a demon in exchange for money.
• Oboro reasoned that the villagers sought the demon’s protection and that its killings were driven by an obsession rather than hunger.
• After the other captives were taken, Oboro entered the shrine and identified its butcher-like demon as Upper Rank Five.
• Upper Rank Five questioned Oboro’s calm attitude toward death and asked what his life was worth.
• Oboro said his sick body had little value but offered Upper Rank Five his priceless soul.

Oboro fought Upper Rank Five while his failing body was briefly empowered by his breathing technique, then drank the demon’s blood to survive. When the Flame Hashira Purgatory Tanjuro and the Water Hashira Kawai Ichie arrived, they found Oboro transforming into a demon by choice.

• Oboro evaded Upper Rank Five’s attacks and used his breathing technique to keep pace despite his ruined body.
• Upper Rank Five summoned flesh-and-blood monsters and prepared to kill Oboro as two Hashira approached.
• Oboro used Soul Breathing, Third Form: Night Parade of a Hundred Demons, to destroy the monsters and briefly incapacitate Upper Rank Five, then collapsed.
• Oboro cut Upper Rank Five’s calf and drank his blood to keep himself alive.
• Purgatory Tanjuro and Kawai Ichie entered, recognized Upper Rank Five, and saw Oboro drinking the demon’s blood.
• Oboro told the Hashira it was bad timing as Muzan’s blood began transforming him into a demon.

Oboro completed his transformation into a demon while resisting Muzan’s control, then demonstrated overwhelming strength against Upper Rank Five. After Oboro’s will reached Muzan through their blood connection and made him recoil, Oboro reflected that his path had only just begun.

• Oboro’s body healed and transformed as Muzan’s cells tried to alter him, but his powerful will suppressed the changes and left him looking human.
• Upper Rank Five, Mireimaru, attacked Oboro from behind, and Oboro struck him through the shrine wall with a single blow.
• Oboro warned Tanjuro and Shiwei to take the fight seriously, then left them to face Upper Rank Five.
• Oboro tested his control over his changing body and spoke Muzan’s name, briefly triggering Muzan’s curse before suppressing it.
• Muzan sensed Oboro’s defiance through their blood connection, suffered a violent backlash, and wondered whether a demon had surpassed him.
• Oboro concluded that Muzan’s power depended on his cells more than his spirit and said his own path had only just begun.

Tanjuro and Ichie struggled to hold Upper Rank Five Mireimaru back from the unconscious villagers, while Oboro watched from nearby. Mireimaru killed Tanjuro and badly wounded Ichie, then taunted him as the battle continued.

• Tanjuro and Ichie fought Mireimaru while keeping the battle away from the unconscious villagers, but Mireimaru’s strength and Blood Demon Arts overwhelmed them.
• Ichie tried to protect Tanjuro, but Mireimaru’s flesh monsters surrounded him and left him unable to help.
• Mireimaru struck Tanjuro in the abdomen and silently killed him as Tanjuro charged with Flame Breathing, Fifth Form: Flame Tiger.
• Ichie attacked Mireimaru with Water Breathing, Eighth Form: Waterfall Basin, but Mireimaru split his body to evade the strike and stabbed Ichie in the side.
• Mireimaru reassembled his body and taunted the badly wounded Ichie about the value of his flesh.

Oboro confronted Upper Rank Five Mireimaru after the demon tried to devour the injured Hashira, then revealed that he was more interested in taking Mireimaru as a resource than meeting Muzan Kibutsuji. Mireimaru fled, and Oboro calmly pursued him.

• Mireimaru mocked the injured Ichie and moved to devour Tanjuro, but stopped when Oboro approached.
• Mireimaru offered Oboro the two Hashira and a recommendation to join the Twelve Kizuki, hoping to avoid making an enemy of him.
• Oboro named Muzan Kibutsuji without being punished and said he was more interested in Mireimaru.
• Oboro used his system to produce items from another world, confirming that he could bring materialized objects across worlds.
• Oboro said he wanted to see if he could take Mireimaru as a usable resource, and Mireimaru fled while Oboro began to pursue him.

Kawai Ichie escaped Qinglin Town with the unconscious Rengoku Tenjuro while Oboro confronted Upper Rank Five, Mireimaru. Oboro subdued Mireimaru and tested his system’s ability to store resources, then turned a piece of demon flesh into a card as he considered seeking Muzan.

• Kawai Ichie carried the wounded Rengoku Tenjuro away from Qinglin Town and sent a Kasugai Crow to report what had happened to the Demon Slayer Corps.
• Mireimaru fled down a country road, then turned back when he realized Oboro was still following him.
• Oboro appeared before Mireimaru at overwhelming speed and tampered with his brain, leaving him conscious but unable to control his body.
• Oboro tried to turn Mireimaru into an item but failed because the system limited the size and weight of resources it could store.
• Oboro cut a piece of Mireimaru’s flesh and converted it into a card describing its demonic powers and side effects.
• Oboro noted that the card was temporary and concluded that he still needed to find Muzan.

Oboro experimented on Mireimaru, converting pieces of his flesh into cards while discovering the limits of his system and witnessing Mireimaru’s memories of becoming a demon. Oboro spared him and left, while Mireimaru recovered and wondered at Oboro’s incomprehensible strength and talk of a soul.

• Oboro carved flesh from Mireimaru and converted it into more than twenty demon flesh and blood cards before reaching the system’s conversion limit.
• Oboro saw Mireimaru’s memories of being forced by a feudal lord to butcher villagers, losing his wife and son, and being saved and turned into a demon by Muzan.
• Oboro judged Mireimaru’s will too weak to yield a Blood Demon Art skill card, then left him alive and told him to tell Muzan that a meeting depended on Oboro’s willingness.
• Mireimaru regained control of his body, punched through his own head as his arm moved, regenerated, and realized he had survived.

Oboro returned to Qinglin Town and killed every villager who had gathered at the shrine, leaving his attendants shocked by his sudden brutality. He walked away and told Chiyoko and Rina to choose whether to follow him or leave.

• Oboro considered how inherited will could strengthen his soul and expand the system's abilities across future worlds.
• Oboro returned to the shrine and found the villagers awake, chaotic, and holding Chiyoko and Rina captive as sacrifices.
• An old man threatened Oboro and demanded to know what the two sword-carrying warriors had done.
• Oboro explained that the villagers had to accept the fate of the path they had chosen, then killed the gathered crowd with his transformed staff.
• Chiyoko and Rina were horrified by Oboro's actions as he walked away and told them to follow him or leave.

Oboro reflected on the stages of his Breathing Technique and how its power surpassed the Demon Slayer world's abilities. Meanwhile, Takemoto Sayuri and Owada reached Qinglin Town, found its villagers slaughtered, and learned that the Upper Rank had already escaped.

• Oboro explained how his Breathing Technique progressed through five realms and could help Demon Slayer swordsmen awaken powerful abilities while reducing the costs of Demon Slayer Marks.
• Takemoto Sayuri hurried toward Qinglin Town after hearing that an Upper Rank Five had appeared and that Shiwei and Rengoku Tanjuro had survived with help from another demon.
• Sayuri arrived at the village near dawn and found Owada, who had searched for the Upper Rank but could not find it.
• Owada and Sayuri concluded that the villagers had been killed by the newly transformed demon rather than the Upper Rank.
• A Kasugai Crow called all Hashira to gather, and Sayuri and Owada agreed to bury the villagers.

Muzan punished Mireimaru for failing to capture the Hashira and ordered him to find Oboro, whose mysterious power and obscured appearance unsettled Muzan. At the Ubuyashiki estate, the Hashira discussed Oboro’s actions and debated what to do about him, leaving his fate unresolved.

• Muzan confronted Mireimaru at his shrine, killed the attendants, and attacked Mireimaru for failing in Qinglin Town.
• Muzan read Mireimaru’s memories but could not see Oboro’s face, then ordered Mireimaru to find him or lose his place among the Twelve Kizuki.
• Muzan decided to have his demons search for the man in a black haori while he avoided approaching Oboro himself.
• At the Ubuyashiki estate, Kuno explained that Oboro had given him the breathing method, while Shiwei and Tanjuro condemned Oboro’s killings and acknowledged that he had spared them.
• Tanjuro and Shiwei accepted responsibility for the mission’s failure, but Kuno said Oboro’s stance worried him more than Muzan’s.
• The Wind Hashira suggested that Kuno knew where Oboro lived, and the gathered Hashira were left weighing whether to go after him.

Oboro tested the Blue Spider Lily’s effect by standing in sunlight, which healed his burns and purged nearly all of Muzan’s cells, returning him to a slightly strengthened human state. He concluded that Muzan could not use the flower to evolve and decided that someone else would need to advance the world’s power system.

• Oboro stood in the rising sunlight despite his demon cells causing his flesh to burn, while Chiyoko and Rina rushed to shield him.
• The Blue Spider Lily healed Oboro’s injuries and removed most of Muzan’s cells, leaving him human and free of the illness that had plagued his body.
• Oboro recognized that Chiyoko and Rina cared for him despite witnessing his merciless side, and he recalled Fills Lily’s feelings from his previous life.
• Oboro reasoned that the Blue Spider Lily would turn Muzan back into a human rather than help him evolve, and that Muzan lacked the will to become a new Demon King.
• Oboro concluded that someone else would have to advance the power system, then told Chiyoko and Rina to leave.

Oboro left Edo Castle and returned to the Entertainment District, but the Demon Slayer Corps tracked him and launched an ambush. He found himself surrounded by all seven Hashira, who had come to execute him.

• Oboro left a shogunate gathering, judged that the Edo regime was nearing collapse, and returned to the Entertainment District days later.
• Oboro spotted a Kasugai Crow following his palanquin and suspected Ubuyashiki Kuno had sent the Demon Slayer Corps after him.
• As night fell, Sayuri crashed Oboro's palanquin and her allies abducted his bearers and maids.
• Sayuri stabbed into the empty palanquin, then discovered Oboro standing several meters away.
• Oboro saw Shiwei, Tanjuro, Sayuri, and four other Hashira surrounding him, bringing the generation's full force against him.

Oboro faced the seven Hashira, praised their resolve, and killed Otomo Issui with a concealed leaf strike after appearing to catch his sword. The remaining Hashira attacked together, and Oboro recognized the strength of their bonds and inherited will as their blades closed in on him.

• Oboro observed the Hashira and discussed their distinctive Breathing Styles, weapons, and ability to sense his demonic aura.
• Rengoku Tenjuro greeted Oboro, then explained that the Hashira had to eliminate him; Otomo Issui and Tsukahara prepared to lead the attack.
• Oboro praised the Hashira's resilient souls and challenged Otomo Issui to prove his resolve by attacking him.
• Otomo Issui used Thunder Breathing, First Form: Thunderclap and Flash, but Oboro secretly cut his throat with a leaf before catching his sword and revealing the deception.
• Sayuri attacked with Light Breathing, Fourth Form: Dazzling Gemlight, while the Iron Hashira, Rengoku Tenjuro, and Kawai Ichie joined the assault.
• As four attacks converged, Oboro recognized that the Hashira's rage and willingness to sacrifice themselves came from their bonds and inherited resolve.

Oboro fought all six Hashira through the night, defeating them with a wooden staff while sparing their lives. At dawn, the Hashira discovered he was human, and Oboro left after calling the battle a lesson, but the Wind Hashira tried to stop him over the deaths he had admitted causing.

• Oboro used precise staff work to disarm and repel the Hashira, then defeated the Stone Hashira and Wind Hashira when they attacked him together.
• The six Hashira continued attacking Oboro through the night, growing exhausted while their determination strengthened.
• At sunrise, the Hashira expected Oboro to burn, but sunlight did not harm him, revealing that he was human.
• Oboro told the Hashira to remember the battle as a lesson and asked them to send his maidservants to his residence in the Entertainment District.
• The Wind Hashira blocked Oboro's path and accused him of killing people, and Oboro admitted killing the Thunder Hashira and villagers before asking whether he would be taken to the magistrate's office.

After the Hashira confronted Oboro, he explained how his battle experience let him exploit their habits, then left them grieving Otomo Issui. At the Ubuyashiki estate, the Hashira debated whether to keep using Oboro’s Breath Control Technique, while Ubuyashiki Kuno warned that Oboro had an unknown purpose and was very dangerous.

• Oboro explained that his experience let him read the Hashira’s movements and expose weaknesses in their swordsmanship, then walked away as the Wind Hashira roared in grief over Otomo Issui.
• Shiwei and the other Hashira reported the battle to Ubuyashiki Kuno, who accepted responsibility for Issui’s death and said he would apologize to him after his own death.
• The Wind Hashira vowed to reject Oboro’s Breath Control Technique and threatened to kill the people close to him, while Shiwei argued that the Hashira needed the strength to defeat Muzan and protect their comrades.
• Rengoku Tenjuro and the Stone Hashira supported passing the Breath Control Technique on to future Demon Slayers, and Ubuyashiki Kuno backed continuing its use.
• Ubuyashiki Kuno judged that Muzan could not control Oboro, but agreed with Sayuri that Oboro had an unknown purpose and urged the Hashira to remain vigilant.

Oboro decided that demons were the only people capable of carrying the new inherited will he wanted to cultivate, one built on the belief that the world was sick and needed to be cured. He searched the Entertainment District’s slums for someone unwilling to accept oppression but found no suitable inheritor, so he continued looking.

• Oboro returned to his residence and concluded that he needed to pass a new inherited will through Muzan and the demons.
• Oboro chose the belief that the world itself was sick and needed to be cured, then asked Chiyoko to prepare to go out.
• Oboro visited a slum brothel but rejected a courtesan whose spirit had surrendered to her circumstances.
• Oboro searched the laborers’ district called Eight Liang and saw workers endure brutal treatment, but found no one who met his standards.
• Oboro considered taking Muzan’s future choices, including Gyutaro and his sister, but decided to keep searching.

Oboro found Zekawa badly wounded after men killed the puppy he had tried to protect. He offered to save the boy and asked him to join in reshaping the world, leaving Zekawa’s response unknown.

• Oboro walked through the Entertainment District with Chiyoko and Rina and saw the exploitation and violence in its slums.
• Oboro found three men fleeing with a puppy after they had beaten Zekawa and struck him with a stone.
• Oboro recognized Zekawa, killed the three men, and brought the puppy’s body to the wounded boy.
• Zekawa mourned the puppy and asked why the world was so cruel as Oboro spoke of its inequality and selfishness.
• Oboro offered to save Zekawa and the puppy’s bond if Zekawa would help correct the world.

Oboro made Zekawa swallow Mireimaru’s demon flesh and revived his dead puppy, Dark Ball, creating his first chosen inheritor. After Oboro left, Zekawa and Dark Ball entered the main street, where Zekawa condemned the people around him and unleashed the puppy’s monstrous transformation.

• Oboro warned Zekawa that pursuing his mission to change the world would bring condemnation, and Zekawa declared that the world was wrong and accepted responsibility.
• Oboro forced Mireimaru’s flesh into Zekawa and fed demon flesh to the dead puppy, then gave both of them his blood essence.
• Zekawa transformed into a demon, and Dark Ball revived as a strange, blackish-crimson puppy.
• Chiyoko told Zekawa to keep Oboro’s name secret until he had achieved his purpose and reminded him that his mission was to save others.
• Zekawa took Dark Ball into the main street, where they encountered scorn and cruelty from the people around them.
• Dark Ball grew to the size of a small house, and Zekawa called the fleeing passersby scum who deserved to die.

Oboro covered up the massacre Zekawa committed in the Entertainment District and continued monitoring the country while training. At the Ubuyashiki estate, Kuno announced Hideo would succeed him and, growing gravely ill, remained unable to understand Oboro’s motives.

• A magistrate’s yoriki reported hundreds dead and wounded in the Entertainment District, and Oboro ordered the news suppressed and the investigation kept limited.
• Oboro saw Demon Slayer Corps swordsmen questioning survivors and concluded Zekawa had left for Edo Castle to attack the ruling class.
• Oboro trained at home and gathered information from magistrate offices and the shogunate while the Corps’ strength grew and its Hashira increased from six to eight.
• Ubuyashiki Kuno summoned the eight Hashira and announced that his twelve-year-old son, Ubuyashiki Hideo, would succeed him after his death.
• Kuno questioned Shiwei about Zekawa, suspected Oboro had created the demon, and coughed up blood as the Hashira urged him to rest.

Ubuyashiki Kuno warned his son Hideo not to make an enemy of Oboro before dying, and the Demon Slayer Corps continued its fight under Hideo’s leadership. As Muzan punished Mireimaru for failing to find Oboro, Doma revealed Oboro’s role in strengthening the Corps, and Muzan sent Doma and another demon to act against him.

• Ubuyashiki Kuno urged Hideo to avoid making an enemy of Oboro unless he joined Muzan or became a demon again, then died with his family and the Hashira grieving beside him.
• Hideo became the new master of the Demon Slayer Corps, whose Hashira intensified their efforts in honor of Kuno and their fallen comrades.
• Muzan blamed the Demon Slayer Corps’ rapid growth for the deaths of many demons and killed Mireimaru after learning he had failed to find Oboro.
• Doma arrived and told Muzan that Oboro had brought Breath Regulation to the Demon Slayer Corps and that the Ubuyashiki Clan had a new leader.
• Doma reported that the slain woman was Sayuri, the Light Hashira, and Muzan ordered him and a composed demon in the shadows to go together.