Chapter Summaries

Tetsu no Sosuke arranged for Goto to watch over his breathing while he slept, then continued training at the Butterfly Estate. With sword-forging work on hold, he focused on conditioning and swordsmanship to make better use of his strength.

• Tetsu no Sosuke decided to ask someone from the Hidden to monitor his breathing while he slept rather than ask Kanae, his sister-in-law, or the girls at the Butterfly Estate.
• Tetsu no Sosuke practiced blowing out air until midnight, believing the exercise was improving his lung capacity.
• The next morning, Tetsu no Sosuke asked Goto to watch over him, and Goto agreed as long as his work and any missions came first.
• Tetsu no Sosuke began the day's physical training, since his sword-forging work was on hold and he wanted to improve his strength and use his body's potential.

Shinobu Kocho ended her sparring with Tetsu no Sosuke and suggested that he ask the Pillars to train him. Tetsu no Sosuke wrote to Giyu Tomioka, then spent the night unable to sleep well as he worried about what lay ahead.

• Shinobu Kocho told Tetsu no Sosuke that her dangerous swordsmanship made their sparring too risky and would no longer help him improve.
• Shinobu Kocho suggested that Tetsu no Sosuke ask the Pillars to spar with him, since he had forged their weapons and they owed him favors.
• After dinner, Tetsu no Sosuke wrote a polite letter asking Giyu Tomioka to train with him and had Goto send it.
• Tetsu no Sosuke went back to blowing into his gourd, but he slept poorly that night as he worried about the training.

Kanae took over helping Tetsu no Sosuke with his sleep-training after learning Goto had been unable to help. Shinobu insisted on joining them that night to keep watch, and Tetsu no Sosuke eventually fell asleep after a long struggle.

• Kanae told Tetsu no Sosuke she would handle his training instead of Goto.
• Shinobu Kocho insisted on joining Kanae that evening to make sure she and Tetsu no Sosuke were not left alone together.
• Kanae and Shinobu questioned Tetsu no Sosuke's erratic breathing and rapid heartbeat, and he apologized as he reined in his thoughts.
• Tetsu no Sosuke took a long time to fall asleep, though he was not woken often afterward.

Tetsu no Sosuke broke a small gourd after training through the night, only to discover that Shinobu Kocho could burst an identical one with ease. Shinobu promised to make him stronger training gourds, and he returned to his conditioning while she wondered why Kanae had admired him from the start.

• Shinobu Kocho and Kanae helped wake Tetsu no Sosuke at the right moments as he trained his Breathing Technique overnight.
• Tetsu no Sosuke broke a twenty-centimeter gourd and explained his method to Shinobu Kocho and Kanae.
• Shinobu Kocho burst an identical gourd with a single breath, exposing the gap between her ability and Tetsu no Sosuke's.
• Shinobu Kocho offered to make medicinal gourds to strengthen his lung training, and Tetsu no Sosuke teased her until she chased him.
• After Shinobu Kocho ran out of stamina, she told Kanae she partly approved of Tetsu no Sosuke and asked why Kanae had admired him so quickly.

Tetsu no Sosuke stabilized his Constant Concentration training at the Butterfly Estate and wrote to request Scarlet Sand Iron so he could forge a Nichirin Blade. A letter from the Village Chief arrived just as he sent his request, and its contents excited him.

• Kanae and Shinobu watched Tetsu no Sosuke sleep each night as he practiced Constant Concentration and progressed to bursting large gourds.
• Tetsu no Sosuke burst Kanao's gourd to show off, and Shinobu caught him, causing another uproar.
• Tetsu no Sosuke stabilized his Constant Concentration, and everyone at the Butterfly Estate celebrated his progress with extra dishes.
• Tetsu no Sosuke wrote a polite letter requesting Scarlet Sand Iron so he could forge a Nichirin Blade.
• Tetsu no Sosuke received a letter from the Village Chief and grew excited as he read it.

Tetsu no Sosuke learned that Swordsmiths had used his Breathing Technique to forge Nichirin Blades that suppressed Demon Regeneration, though the process remained difficult and inconsistent. Unable to solve the problems or find Tanjiro's family, he asked the Village Chief to let him visit.

• Tetsu no Sosuke read that Swordsmiths had forged Nichirin Blades capable of suppressing Demon Regeneration.
• Tetsu no Sosuke learned that only three Swordsmiths had succeeded, that forging and recovery took many days, and that the blades varied in strength.
• Tetsu no Sosuke considered the difficulties but could not offer a solution, noting that he still had not found Tanjiro's family.
• Tetsu no Sosuke wrote to the Village Chief, encouraged the Swordsmiths to keep trying, and requested permission to visit the village.
• Tetsu no Sosuke sent the letter with someone from the Hidden.

Tetsu no Sosuke received a large supply of Scarlet Sand Iron and began forging his own blade. Kanae came to call him for breakfast but stayed to watch him work.

• Tetsu no Sosuke received Scarlet Sand Iron from a Hidden member and was surprised by how much he had been given.
• Tetsu no Sosuke lit the furnace and began forging with the Heavenly Crafting Hammer.
• Kanae arrived to call Tetsu no Sosuke to breakfast and found him hammering iron.
• Kanae watched Tetsu no Sosuke forge and became so absorbed that time slipped by.

Tetsu no Sosuke forged a Nichirin Blade from Scarlet Sand Iron, finishing its shape and placing it in the furnace. When he turned around, Kanae and Shinobu Kocho were standing nearby.

• Shinobu Kocho teased Kanae about watching Tetsu no Sosuke, and Kanae caught her and tickled her.
• Tetsu no Sosuke used Gale Sun and his Heavenly Craft tools to remove every impurity from the Iron Material in two hours.
• Tetsu no Sosuke began the second stage of hammering and shaped the Scarlet Sand Iron into a Nichirin Blade.
• Tetsu no Sosuke placed the blade in the furnace and found Kanae and Shinobu Kocho standing behind him.

Tetsu no Sosuke returned to find Kanae and Shinobu Kocho waiting with food, and he learned Kanae had scolded Shinobu. As he shared a quiet moment with Kanae, Shinobu came back to stop them from being alone together.

• Kanae and Shinobu Kocho brought Tetsu no Sosuke food after he lost track of time.
• Tetsu no Sosuke heard Shinobu muttering that Kanae was a monster, and Shinobu ran off crying when he called her words strange.
• Kanae told Tetsu no Sosuke she had scolded Shinobu, and he agreed without asking why.
• Kanae led Tetsu no Sosuke to the veranda and went to pour him tea.
• Tetsu no Sosuke gazed fondly at Kanae until Shinobu returned and warned them not to do anything improper.

Tetsu no Sosuke sharpened and assembled a Nichirin Blade, earning a sharpness level of four and a new Heavenly Artisan skill. After receiving Giyu Tomioka’s brief reply about being ready, he decided to visit him in person later.

• Tetsu no Sosuke used Heavenly Artisan Skill: Blade Sharpening to hone the blade and worked on its other components over the next two days.
• Giyu Tomioka replied that he would be ready whenever Tetsu no Sosuke was, and Tetsu no Sosuke chose not to write back.
• Tetsu no Sosuke assembled the Nichirin Blade and forged his first weapon with sharpness level four.
• Tetsu no Sosuke gained forty points each in strength, constitution, agility, and speed, and received Heavenly Artisan Skill: Mechanisms.

Tetsu no Sosuke received an advanced book on mechanisms and discovered that his Nichirin Blade had turned red after being forged with the Bloodforging Method. After deciding to visit Giyu Tomioka, he left the Butterfly Estate with Kanae.

• Tetsu no Sosuke studied the advanced volume on small mechanisms and gained new insights.
• Tetsu no Sosuke found that his Nichirin Blade had turned blazing red and felt unusually light and natural in his hand.
• Tetsu no Sosuke wondered what unique enhancement the blade gave him and noted that the Iron Hammer’s other parts retained their usual weight.
• Tetsu no Sosuke told Kanae he planned to visit Giyu Tomioka, and Kanae packed before they left the Butterfly Estate together.

Tetsu no Sosuke and Kanae traveled to Giyu Tomioka’s residence after Kanae explained how Sosuke had eased Shinobu’s stress and helped her regain her smile. They arrived to find Giyu pacing expressionlessly outside his gate.

• Tetsu no Sosuke left the Butterfly Estate with Kanae while Shinobu watched them go with visible dismay.
• Kanae told Tetsu no Sosuke that his care and jokes had eased Shinobu’s pressure and helped bring back her smile.
• Kanae thanked Tetsu no Sosuke for cherishing Shinobu, and he said he believed things would improve.
• Tetsu no Sosuke and Kanae arrived at Giyu Tomioka’s residence and found him pacing back and forth at the gate.

Giyu Tomioka waited at the gate for Tetsu no Sosuke and Kanae, congratulated Kanae, and explained that he would train Tetsu no Sosuke whenever he was not on a mission. The three settled on Giyu helping him improve until Giyu felt he could no longer do so.

• Kanae and Tetsu no Sosuke saw Giyu Tomioka waiting at the gate and wondered if he had come to meet them.
• Tetsu no Sosuke took Kanae by the hand and approached Giyu, who confirmed that he had waited because they said they would come.
• Giyu congratulated Kanae, making her blush, then led them inside.
• Giyu told Tetsu no Sosuke he would train with him whenever he was not assigned a mission, until he could no longer help him improve.
• Tetsu no Sosuke agreed, and Kanae thanked Giyu for his help.

Tetsu no Sosuke and Giyu Tomioka began a real-sword sparring match in the courtyard while Kanae watched. Giyu opened with a Water Breathing strike, and Tetsu no Sosuke dodged it by flipping backward.

• Kanae watched over Tetsu no Sosuke and Giyu Tomioka as they prepared to spar with real swords.
• Tetsu no Sosuke gave Giyu an ordinary blade to spare his Nichirin Blade from wear.
• Giyu attacked with Water Breathing—Form One: Water Surface Slash, aiming for Tetsu no Sosuke's neck.
• Tetsu no Sosuke flipped backward to evade the slash, which swept past his chest.

Tetsu no Sosuke endured a brutal day of training with Giyu Tomioka and was left battered. Kanae treated his wounds and struggled to hide her anger, while Tetsu no Sosuke comforted her.

• Giyu Tomioka repeatedly struck Tetsu no Sosuke during training, leaving him covered in cuts and bruises.
• Kanae treated Tetsu no Sosuke's injuries after dinner, carefully applying medicine and bandages.
• Kanae admitted that she knew Giyu Tomioka had held back but still felt angry about Tetsu no Sosuke being hurt.
• Tetsu no Sosuke took Kanae's hand and comforted her as she rested her head on his shoulder.

Kanae comforted Tetsu no Sosuke as he recovered from his wounds, and they shared a tender moment before Giyu Tomioka quietly withdrew. Tetsu no Sosuke then resumed training under Shinobu Kocho and Giyu Tomioka.

• Kanae regretted being unable to take Tetsu no Sosuke’s place, and he told her that her words made him want to devote his life to loving her.
• Tetsu no Sosuke cupped Kanae’s cheeks and kissed her forehead as they held each other in silence.
• Giyu Tomioka arrived with medicine, saw their silhouettes, and returned to his room without interrupting them.
• Tetsu no Sosuke began training again, receiving precise guidance from Shinobu Kocho and repeated sparring lessons from Giyu Tomioka.

After completing his training with Giyu Tomioka, Tetsu no Sosuke returned to the Butterfly Estate with Kanae and reunited with Shinobu Kocho. A letter from Kawahara Chintetsu invited him back to the Swordsmith Village, though he was no longer considered one of its swordsmiths.

• Tetsu no Sosuke improved through weeks of sparring with Giyu Tomioka until Giyu said he had taught him everything he could.
• Giyu Tomioka escorted Tetsu no Sosuke and Kanae to the gate, and they returned safely to the Butterfly Estate.
• Shinobu Kocho inspected Tetsu no Sosuke and questioned him about whether he had done anything unusual with Kanae; he denied it.
• Shinobu Kocho told Tetsu no Sosuke that a letter had arrived from the Swordsmith Village.
• Tetsu no Sosuke read Kawahara Chintetsu's reply, which said he could return whenever he wished but was no longer considered a swordsmith of the village.

Tetsu no Sosuke returned toward the Swordsmith Village under escort by members of the Hidden, while Kanae and Shinobu Kocho left on separate missions. The exhausting handoffs took five days to reach a Wisteria House, and the journey continued.

• Tetsu no Sosuke told Kanae about the secret procedures Swordsmiths needed to follow to return to the Swordsmith Village, and she agreed he should go back.
• Kanae and Shinobu Kocho received new missions, so neither could accompany Tetsu no Sosuke when he set out the next morning.
• A young member of the Hidden carried Tetsu no Sosuke and his Iron Hammer to the next handoff, where a young woman took over and collapsed after the journey.
• The members of the Hidden struggled to carry Tetsu no Sosuke through a series of handoffs until they reached a Wisteria House at the end of the day.
• Tetsu no Sosuke continued the journey the following day, and the trip took five days to reach the Wisteria House.

Tetsu no Sosuke returned to the Swordsmith Village to check on Kotetsu's Automaton Puppet and the three Swordsmiths who had forged blades that suppressed Demon Regeneration. Kawahara Chintetsu told him the project had failed and the three Swordsmiths were in bad shape.

• Tetsu no Sosuke reached the Swordsmith Village and went to see Kawahara Chintetsu.
• Kawahara Chintetsu teased Tetsu no Sosuke about his relationship with the Flower Pillar and doubted he could become a Pillar.
• Tetsu no Sosuke told Kawahara Chintetsu that he had returned to check on the Swordsmiths.
• Kawahara Chintetsu said the project had failed and that the three Swordsmiths were in bad shape.

Tetsu no Sosuke learned that the three swordsmiths who used the Breath of the Sun forging method had been left too weak to get out of bed, forcing him to set the method aside. Back in the Swordsmith Village, he wrote to Shinobu Kocho for help and reunited with Kotetsu, who told him the village admired his special Nichirin Blades.

• Kawahara Chintetsu told Tetsu no Sosuke that the three swordsmiths had suffered severe strain from forging another Nichirin Blade with the Breath of the Sun.
• Tetsu no Sosuke saw the three weakened swordsmiths and heard Kawahara Chintetsu advise him to find talented children and guide them if he wanted to continue the method safely.
• Tetsu no Sosuke wrote to Shinobu Kocho asking her to treat the swordsmiths or send a prescription, then wrote to Kanae to say he had arrived safely.
• Tetsu no Sosuke sat in the Sword Forging Shed, troubled by the need to suspend the forging method, until Kotetsu came to visit him.
• Kotetsu told Tetsu no Sosuke that the villagers admired his powerful Nichirin Blades and regretted that he had become a Swordsman instead of remaining a Swordsmith.