Chapter Summaries

Tetsu no Sosuke and Kanae traveled to Mt. Sagiri, where he hoped to find Urokodaki Sakonji and learn whether Iron Head and his family had survived. After seven days, they found no house but discovered a masked man sitting on a boulder.

• Tetsu no Sosuke left the Butterfly Estate with Kanae after only three days, eager to reach Mt. Sagiri.
• Tetsu no Sosuke worried that finding Iron Head's family on Mt. Sagiri might confirm that the tragedy he feared had happened.
• Kanae comforted Tetsu no Sosuke by taking his hand without asking what troubled him.
• Tetsu no Sosuke and Kanae searched Mt. Sagiri for seven days before finding a man in a Tengu Mask sitting on a boulder.

Urokodaki Sakonji questioned why Tetsu no Sosuke wanted to become a swordsman and urged him to search his heart for his true purpose. As they continued toward Urokodaki Sakonji's home, Tetsu no Sosuke wondered whether his tangled thoughts were keeping him from wielding his sword purely.

• Urokodaki Sakonji met Kanae and Tetsu no Sosuke and praised Tetsu no Sosuke's work as a swordsmith.
• Urokodaki Sakonji asked why Tetsu no Sosuke wanted to fight demons instead of serving from the rear.
• Tetsu no Sosuke said he wanted to protect humanity, then admitted that he wanted to protect Kanae.
• Urokodaki Sakonji told Tetsu no Sosuke to question his heart repeatedly until he discovered his true purpose and strength.
• Tetsu no Sosuke took Kanae's hand and wondered whether his many thoughts were preventing him from making his sword pure.

Tetsu no Sosuke and Kanae arrived at Urokodaki Sakonji’s home and found Kamado Tanjiro training there. Tetsu no Sosuke struggled with guilt over not finding Tanjiro’s family and asked how long Tanjiro had been training with Urokodaki Sakonji.

• Tetsu no Sosuke saw Kamado Tanjiro chopping firewood and realized he had already come to Urokodaki Sakonji.
• Kamado Tanjiro greeted Tetsu no Sosuke and Kanae, and they introduced themselves.
• Urokodaki Sakonji identified Tetsu no Sosuke as a swordsmith and Kanae as a Demon Slayer Corps swordsman.
• Tetsu no Sosuke felt guilty as he wondered whether he could have found Tanjiro’s family and how long Tanjiro had been able to smile.
• Tetsu no Sosuke asked Urokodaki Sakonji whether Tanjiro had been training with him all this time.

Urokodaki Sakonji explained why he had kept Tanjiro’s demon sister alive, while Kanae and Tetsu no Sosuke questioned the decision. Kanae accepted Tanjiro’s account of his sister protecting him as a convincing reason, then asked one more question.

• Urokodaki Sakonji told Tetsu no Sosuke that Tanjiro had arrived a month and a half earlier.
• Urokodaki Sakonji revealed that Tanjiro’s sister was a demon, and Kanae gripped her Nichirin Blade as the atmosphere grew tense.
• Tanjiro pleaded for his sister’s life, and Tetsu no Sosuke asked why Urokodaki Sakonji and Giyu Tomioka had spared her.
• Urokodaki Sakonji explained that Tanjiro’s sister had attacked another demon to protect him, and that he hoped to teach her to protect humans.
• Kanae asked Tanjiro if his sister had protected him before; after he confirmed it, Kanae said that was convincing and asked another question.

Kanae spared Nezuko after Tanjiro swore she had never eaten anyone and had protected her brother, but said she would judge her for herself. Tanjiro chopped firewood outside while Kanae and Tetsu no Sosuke went into Urokodaki Sakonji’s house and saw Nezuko sleeping.

• Kanae said she would spare Nezuko for now because she had no blood on her hands, though she would kill her if she became a threat.
• Tanjiro thanked Kanae and said he believed Nezuko would not let her down.
• Urokodaki Sakonji said there was no spare room, so Kanae and Tetsu no Sosuke agreed to stay together.
• Tanjiro watched Kanae and Tetsu no Sosuke shyly hold hands and excitedly remarked on their relationship.
• Tanjiro stayed outside to chop firewood while Kanae and Tetsu no Sosuke entered the house.
• Kanae saw Nezuko sleeping with bamboo between her teeth and said she was likely conserving energy.

Tetsu no Sosuke asked Urokodaki Sakonji to teach him the ten forms of Water Breathing so he could make an Automaton Puppet, and Urokodaki agreed to demonstrate them. As Tetsu no Sosuke and Kanae discussed Nezuko’s possible future, they wondered whether her deepest feelings would remain kind once she woke.

• Tetsu no Sosuke told Urokodaki Sakonji he needed a deeper understanding of all ten Water Breathing forms, and Urokodaki agreed to teach him over the next few days.
• After lunch, Urokodaki took Tanjiro into the mountains to train while Tetsu no Sosuke and Kanae prepared their shared room.
• Tetsu no Sosuke laid bedding on the floor and told Kanae she could sleep in the bed.
• Kanae said she wanted to see whether Nezuko could overcome her demonic urges, and she explained that she hoped demons could find peace.
• Tetsu no Sosuke suggested that Nezuko’s continued sleep might already show there was still kindness in her heart.

Tetsu no Sosuke reflected on what he truly wanted and realized he wanted to protect the people within his reach. He accepted that he could not save the whole world, but resolved to keep those close to him from being swept into sorrow.

• Tetsu no Sosuke continued his Swordsmanship training while thinking over Urokodaki Sakonji's advice, with Kanae leaning against him.
• He recalled how his goals had shifted from protecting himself to forging blades, helping Kanae, and strengthening the Demon Slayer Corps.
• Tetsu no Sosuke wondered if his true desire was world peace, then recognized that he could not protect everyone.
• He resolved to understand his limits and do everything he could to protect the people within his reach.

Tetsu no Sosuke struggled through sword training, convinced that an unseen force was disrupting his movements while Kanae insisted he looked normal. When Urokodaki Sakonji and a battered Tanjiro returned, Sosuke worried that Tanjiro might be spared his suffering if he still had a choice.

• Tetsu no Sosuke thought he had discovered something, but his sword slash felt ordinary and he concluded that someone had tricked him.
• Kanae told Tetsu no Sosuke to keep looking, and he resumed his sword practice.
• Tetsu no Sosuke felt blocked and awkward with every swing, but Kanae said his movements looked the same as before.
• Tetsu no Sosuke saw Urokodaki Sakonji and bruised, battered Tanjiro returning, then worried that Tanjiro might not have to suffer if he could still choose.
• Tanjiro waved enthusiastically to Tetsu no Sosuke and Kanae.

After Tanjiro returned from training, Tetsu no Sosuke and Kanae settled in for the night, but Kanae worried about him sleeping on the cold floor and pulled him into bed. The chapter ended with Tetsu no Sosuke trying unsuccessfully to sleep beside her.

• Tetsu no Sosuke asked Tanjiro how training had gone, and Tanjiro said he had been beaten badly before hurrying off to make dinner.
• After dinner, Tetsu no Sosuke and Kanae returned to their room to sleep.
• Tetsu no Sosuke woke during the night because the bedding on the floor felt icy and hard.
• Kanae admitted she had been worrying about his comfort and pulled him into bed.
• Kanae told Tetsu no Sosuke to stop letting his thoughts wander and go to sleep, but her scent kept him awake.

Tetsu no Sosuke spent a restless night with Kanae, then began learning the ten forms of Water Breathing from Urokodaki Sakonji. He watched closely and asked for demonstrations whenever he missed a movement.

• Kanae fell asleep in Tetsu no Sosuke's arms, while he stayed awake and still whenever she stirred.
• Tetsu no Sosuke and Kanae got up the next morning, and Urokodaki Sakonji teased them about restraint.
• Tanjiro left before breakfast to train at the summit of Mt. Sagiri.
• Urokodaki Sakonji demonstrated the ten forms of Water Breathing to Tetsu no Sosuke in a clearing.
• Tetsu no Sosuke tried to memorize each form and asked Urokodaki Sakonji to repeat movements he had missed.

Over seven days, Tetsu no Sosuke memorized the ten Water Breathing forms and broke through a barrier in his swordsmanship, though Kanae remained uneasy about his progress. The Hidden then arrived at Urokodaki Sakonji’s home and built a Sword Forging Shed for Tetsu no Sosuke.

• Tetsu no Sosuke watched Urokodaki Sakonji demonstrate Water Breathing each morning and practiced his swordsmanship each afternoon while Kanae watched.
• After seven days, Tetsu no Sosuke had memorized all ten forms and started thinking about reproducing them through Mechanism Arts.
• Tetsu no Sosuke overcame the restraints in his sword swings, making his slashes faster, stronger, and capable of severing a demon’s neck.
• Kanae celebrated Tetsu no Sosuke’s breakthrough but remained uneasy about it.
• Members of the Hidden arrived, and Tanjiro learned they had brought supplies for Tetsu no Sosuke.
• The Hidden spent the afternoon building a Sword Forging Shed near Urokodaki Sakonji’s cottage.

Tetsu no Sosuke prepared to build an Automaton Puppet while he and Kanae lay awake discussing her fear that he would join the Demon Slayer Corps and die on a mission. Kanae reassured him that Shinobu was strong, and their conversation ended with her laughing at his grumbling.

• Tetsu no Sosuke gathered the parts for two Automaton Puppets and planned to begin making the core the next day.
• Unable to sleep, Tetsu no Sosuke pondered how to combine the ten forms of Water Breathing while Kanae watched him anxiously.
• Kanae told Tetsu no Sosuke that his improving swordsmanship made her worry he would soon join the Demon Slayer Corps and die.
• Tetsu no Sosuke said he understood her fear because he felt the same dread when Kanae went on missions.
• Kanae said she was more worried about Tetsu no Sosuke than she had been about Shinobu, then reminded him that Shinobu was strong.

Kanae worried about Tetsu no Sosuke facing danger, but he reassured her and told her about a Demon he had once encountered alone. As Tetsu no Sosuke fell asleep, Kanae understood his courage and devotion more deeply and kissed his cheek.

• Kanae admitted that waiting and being unable to protect Tetsu no Sosuke made her worry despite believing in him.
• Tetsu no Sosuke told Kanae about encountering a Demon alone while bringing her a sword from Swordsmith Village.
• Tetsu no Sosuke fell asleep before finishing his story as Kanae rested against his chest.
• Kanae remembered how Tetsu no Sosuke had searched desperately for her after her encounter with Upper Moon Two and realized he had faced danger before without fear.
• Kanae kissed Tetsu no Sosuke on the cheek while he slept.

Tetsu no Sosuke worked on the Automaton Puppet’s core mechanism while Kanae watched and Urokodaki Sakonji endured the noise. When Tanjiro visited the Sword Forging Shed, Tetsu no Sosuke invited him to help assemble the parts.

• Tetsu no Sosuke began forging the Automaton Puppet’s core mechanism in the Sword Forging Shed.
• Kanae watched Tetsu no Sosuke work while Urokodaki Sakonji drank tea outside and endured the intermittent hammering.
• Tanjiro approached the shed and asked Tetsu no Sosuke whether he was making the Automaton Puppet.
• Tetsu no Sosuke explained that he was forging the puppet’s core and asked Tanjiro to assemble parts using a blueprint.
• Tanjiro opened the boxes, studied the blueprint, and began fitting together the parts.

Tanjiro helped Tetsu no Sosuke assemble the puppet and became so absorbed in the work that the afternoon passed. Afterward, he tried to lift Sosuke’s massive Hammer Sword and watched Sosuke reveal its hidden Nichirin Blade.

• Tanjiro followed the blueprints and assembled parts while Tetsu no Sosuke and Kanae watched.
• Kanae asked whether the work would interfere with Tanjiro’s training, and Tetsu no Sosuke said he needed time to rest.
• Tanjiro looked up and realized the afternoon had passed and Tetsu no Sosuke and Kanae had gone training.
• Tetsu no Sosuke returned with his Hammer Sword and let Tanjiro try lifting it.
• Tanjiro barely raised the Hammer Sword before losing his balance and dropping it.
• Tetsu no Sosuke triggered the weapon’s mechanism and pulled out a Nichirin Blade, astonishing Tanjiro.

Tetsu no Sosuke explained his Hammer Sword to Tanjiro, who kept helping him build the Automaton Puppet while training with Urokodaki Sakonji. When Sosuke completed the six-armed puppet, he activated it and sent Tanjiro flying with a hammer blow, revealing what the puppet was used for.

• Tetsu no Sosuke explained that his Hammer Sword concealed a Nichirin Blade inside its hammer-shaped sheath and that he relied on strength to fight demons.
• Tanjiro praised Sosuke's strength, then hurried off to make dinner as Kanae remarked on his honest eyes.
• Tanjiro returned each day to help assemble the Automaton Puppet and continued afternoon training with Urokodaki Sakonji.
• Tetsu no Sosuke completed the puppet's core and assembled its body, legs, head, and six arms.
• Tetsu no Sosuke activated the finished Automaton Puppet, and one of its hammer blows sent Tanjiro flying.

Tetsu no Sosuke finished an operating guide for the Automaton Puppet and found Tanjiro studying it late at night. Tanjiro questioned how the puppet moved so quickly, and Tetsu no Sosuke asked why he was still awake.

• Tetsu no Sosuke wrote instructions for operating the puppet, expecting he might need to create guides for other training puppets.
• After finishing before midnight, Tetsu no Sosuke went outside for air while Kanae slept.
• He found Tanjiro beside the puppet, reviewing their sparring and wondering why he could not match or dodge its movements.
• Tanjiro noticed Tetsu no Sosuke and asked if he was still awake, and Tetsu no Sosuke asked him the same.

Tanjiro reassured Tetsu no Sosuke that he would keep pursuing his goals, and Sosuke promised to forge him a Nichirin Blade after he grew stronger and passed the final test. Sosuke and Kanae left Mt. Sagiri after Urokodaki Sakonji urged Sosuke to keep searching within himself.

• Tetsu no Sosuke told Tanjiro to train with the Automaton Puppet in Swordsmith Village when he was ready.
• Tanjiro told Tetsu no Sosuke not to worry about him and vowed to turn Nezuko human and find the demon responsible for killing his family.
• Tetsu no Sosuke encouraged Tanjiro to keep moving forward and promised to forge him a Nichirin Blade after he passed the final test.
• Tanjiro went to the mountaintop to train the next morning while Tetsu no Sosuke and Kanae prepared to leave.
• Kanae visited the sleeping Nezuko, then Tetsu no Sosuke and Kanae said goodbye to Urokodaki Sakonji.
• Urokodaki Sakonji urged Tetsu no Sosuke to keep digging deeper, and Tetsu no Sosuke left with Kanae, who asked if he would say goodbye to Tanjiro.

After returning to the Butterfly Estate, Kanae and Tetsu no Sosuke were greeted by a dejected Shinobu, who believed their long journey together meant they had become intimate. Shinobu’s suspicions grew until she suddenly threw herself at Kanae after dinner.

• Tetsu no Sosuke and Kanae returned to the Butterfly Estate after a snowy journey home.
• Shinobu Kocho saw them arrive and went inside without welcoming them, seeming despairing.
• At dinner, Shinobu watched Tetsu no Sosuke dote on Kanae and grew jealous.
• Shinobu recalled rumors that Tetsu no Sosuke and Kanae had shared a room at Urokodaki Sakonji’s home during their month away.
• After dinner, Shinobu cried out to Kanae and threw herself at her, and Kanae asked if she had missed her.

Shinobu agreed to sleep with Kanae, while Tetsu no Sosuke returned to his room and read three letters. Kyojuro Rengoku asked him to repair his damaged Nichirin Blade, leaving Sosuke to await his arrival.

• Kanae persuaded Shinobu to sleep with her, and Shinobu glared at Tetsu no Sosuke when he ruffled her hair.
• Tetsu no Sosuke returned to his courtyard after the sisters came back that evening.
• Tetsu no Sosuke read the Village Chief's advice to balance his puppet work with sword-forging and training, then wrote a reply.
• Tetsu no Sosuke read Kanroji Mitsuri's invitation to train and sent her a perfunctory response.
• Tetsu no Sosuke read Kyojuro Rengoku's letter asking him to repair his damaged Nichirin Blade.