Chapter Summaries

Kanae coaxed Giyu and Shinobu into sharing the hot spring, then deliberately drew Giyu into an embrace. Giyu fled in embarrassment, while Kanae watched with a satisfied smile.

• Giyu tried to refuse the mixed bathing, but Kanae persuaded him by claiming the village chief said they needed to relax together to forge the best sword.
• Giyu entered the hot spring first and turned his back while Kanae and Shinobu joined him.
• Kanae spoke gently with Giyu until he relaxed, then slipped into his arms and told him she liked how warm and safe he felt.
• Giyu shoved Kanae away, climbed out of the hot spring, and fled without looking back.
• Shinobu sighed with relief, while Kanae watched Giyu leave with a victorious smile.

Kanae comforted Shinobu after learning that she loved Giyu, then proposed that they love him together and support him as allies. As the sisters happily played in the hot spring, Giyu listened to their laughter and felt his unsettled mood ease.

• Kanae approached Shinobu in the hot spring and asked whether she was nervous because of Giyu and liked him.
• Shinobu confessed that she loved Giyu but felt guilty because she believed he belonged with Kanae.
• Kanae reassured Shinobu that her feelings were natural and invited her to love Giyu together with her.
• Kanae and Shinobu formed an alliance to win over Giyu and playfully splashed one another in the spring.
• Giyu listened to the sisters' laughter from outside the annex and felt calmer, smiling faintly beneath the moon.

Muzan Kibutsuji promoted the doctor to Upper Rank Seven after the doctor proposed using mass human trials and Muzan’s blood to develop immunity to sunlight. Newly empowered, Upper Rank Seven left the Infinity Castle plotting to make Muzan his own test subject and become the world’s sole ultimate life-form.

• Muzan summoned the doctor and demanded progress on overcoming sunlight, threatening him when he had no cure.
• The doctor proposed searching for a genetically exceptional human through large-scale trials and using Muzan’s blood to create a sunlight-adaptive subject.
• Muzan approved the plan, gave the doctor powerful blood, and promoted him to Upper Rank Seven.
• After leaving the Infinity Castle, Upper Rank Seven secretly vowed to turn Muzan into a test subject and eliminate the need for two ultimate life-forms.

Giyu Tomioka endured an embarrassing breakfast with Kanae Kocho and Shinobu Kocho after the previous night's hot spring incident, while Kanae continued teasing him. A mission from the Master sent the three to Mount Sagiri to meet Tamayo, giving Giyu an eager escape from the awkward situation.

• Giyu Tomioka and Shinobu Kocho sat through breakfast, both flustered by memories of the previous night, while Kanae Kocho teased them about it.
• Kanae recalled proposing a sister alliance with Shinobu to win Giyu's affection and defend their shared assets.
• Tecchin Tecchikawahara arrived with the sisters' unfinished swords and joked that Giyu should cherish the two women beside him.
• Kanzaburo crashed into the dining room and delivered the Master's order for Giyu, Kanae, and Shinobu to go to Mount Sagiri to discuss important matters with Tamayo.
• Giyu eagerly ordered the group to leave at once.

Giyu Tomioka brought the Kocho Sisters to Tamayo’s laboratory, where Tamayo and Shinobu Kocho investigated his demon-killing blood. Tamayo proposed combining it with blood from Muzan Kibutsuji or the Twelve Kizuki to create a weapon, and Giyu offered his blood as preparations began.

• Giyu Tomioka led the Kocho Sisters through a hidden passage to Tamayo’s laboratory, where Yushiro angrily challenged their presence before Tamayo ordered him to stand down.
• Tamayo showed that Giyu’s blood, after a hundred days, barely harmed a chained One-Eyed Demon because its activity declined rapidly outside his body.
• Shinobu Kocho and Tamayo discussed ways to preserve the blood’s activity, but concluded that conventional methods were insufficient.
• Tamayo proposed using the nearly eternal cells in Muzan Kibutsuji’s blood or the Twelve Kizuki’s blood as a culture medium for Giyu’s blood.
• Giyu calmly offered his arm for a blood draw, and Tamayo warned him to be extremely careful around the Twelve Kizuki.

Sabito tracked a demon stealing medicinal ingredients at Yokohama Port and confronted Yaoshi, an Upper Rank Seven demon. Yaoshi incapacitated Sabito with a pink mist and a bodily transformation, leaving him helpless as Yaoshi escaped.

• Sabito followed the scent of rare medicinal ingredients through Yokohama Port and found a man in a lab coat inspecting a stolen shipment.
• The man mentioned Lord Muzan and Giyu Tomioka, prompting Sabito to attack him with Water Breathing techniques.
• The man released a pink mist that impaired Sabito, but Sabito still managed to sever his arm.
• The man regenerated his arm and revealed that his medicine was transforming Sabito's body, draining his strength and leaving him unable to fight.
• The man introduced himself as Yaoshi, of Upper Rank Seven, called Sabito Test Subject Number One, and disappeared into the shadows.

Giyu Tomioka discovered that a powerful demon had killed every resident of a village with mysterious green particles. When Kanzaburo reported that Sabito had been gravely wounded by an Upper Rank demon, Giyu suspected it was the same demon and raced toward Mount Sagiri.

• Giyu Tomioka found a village where more than a hundred residents had died without visible wounds.
• Giyu used the Transparent World to see green particles throughout the village and recognized them as a demon's Blood Demon Art.
• Kanzaburo crashed in front of Giyu and delivered the Master's urgent order to return to Mount Sagiri.
• Kanzaburo reported that Sabito had encountered an Upper Rank demon and was gravely wounded, with his life in danger.
• Giyu suspected the demon that attacked Sabito was responsible for the village deaths and vanished toward Mount Sagiri.

Giyu Tomioka returned to Sakonji Urokodaki’s cabin fearing Sabito was dead, only to discover that a pink virus had transformed Sabito into a girl. After learning that killing or capturing the demon who infected him was the only way to reverse it, Giyu set out to find him.

• Giyu Tomioka arrived at Sakonji Urokodaki’s cabin and feared the grief-stricken Sakonji and Kagaya Ubuyashiki meant Sabito had died.
• Shinobu Kocho pulled Giyu into the cabin, where he found Sabito transformed into a girl and mistook the situation for a bizarre misunderstanding.
• Kanae Kocho explained that newly appointed Upper Rank Seven, “Yaoshi,” had infected Sabito with a virus that changed him into a girl.
• Tamayo explained that killing Yaoshi or capturing him to make an antidote were the only ways to reverse the transformation.
• Giyu left to find Yaoshi and cut off his head.

Sabito demanded to hunt down the quack who had transformed her, but Giyu’s blunt remarks and Kanae’s suggestion that she learn Flower Breathing sent her into a furious collapse. Kagaya assigned Giyu full responsibility for hunting Upper Rank Seven, and Giyu immediately left for the mountain forest.

• Sabito tried to stop Giyu from leaving and insisted she would kill the quack herself once she recovered.
• Giyu told Sabito she was too weak to fight and should stay behind to train, prompting her to erupt in anger.
• Kanae soothed Sabito and offered to teach her Flower Breathing, but imagining herself using it made Sabito cough up blood.
• Kagaya placed Giyu in full charge of the mission to hunt Upper Rank Seven and promised him the Corps' support.
• Giyu accepted the mission and vanished into the mountain forest.

Yaoshi’s rapidly evolving viruses caused bizarre outbreaks across the Demon Slayer Corps and overwhelmed the newly established Butterfly Mansion, where Shinobu Kocho and Tamayo struggled to develop a cure. Giyu Tomioka found a clue pointing to Tokyo, but an urgent report revealed that Yaoshi had unleashed a new virus that made poisoned Corps members attack people they feared seeing.

• A wave of bizarre illnesses spread through Corps outposts and towns, prompting desperate requests for help at the Butterfly Mansion.
• Kanae Kocho managed the chaos at the overcrowded mansion while Shinobu Kocho and Tamayo failed to stop the viruses from evolving beyond their antidotes.
• Giyu Tomioka found a scalpel bearing Yaoshi’s blood and traced a faint violet-perfume scent to the Imperial Capital, Tokyo.
• Kanzaburo brought Giyu an urgent report that Yaoshi’s new blue virus had driven poisoned Corps members mad and made them attack one another.
• Giyu gripped the scalpel and turned his attention toward Tokyo with a deathly calm.

After despairing over her transformed, weakened body, Sabito took Sakonji Urokodaki’s lesson about Water Breathing to heart and adapted her training to her new form. A month later, she defeated Kanae Kocho in a sparring match and resolved to kill Yaoshi.

• Sabito refused food, drink, and training, but after eating the meal Sakonji Urokodaki left outside her door, she read his note and realized she needed to adapt like water rather than fight her new body like stone.
• Sabito emerged the next morning determined to train and spent twelve hours beneath a waterfall, learning to move with the current.
• A month later, Sabito sparred with Kanae Kocho and used modified Water Breathing forms to defeat her.
• Sabito looked to the moon and vowed to kill Yaoshi herself.

Yaoshi reviewed his failed experiments and concluded that he needed a naturally exceptional test subject, while suspecting the Blue Spider Lily bloomed only in daylight. He abandoned his plague campaign and set out for Mount Kumotori disguised as a doctor, hoping to find villagers who knew of the flower.

• Yaoshi examined reports showing that his subjects either exploded or became mindless after receiving his improved blood.
• Yaoshi realized that quantity would not solve his problem and decided he needed an exceptionally high-quality subject.
• Yaoshi theorized that the Blue Spider Lily bloomed during the day, explaining why Muzan had never found it.
• Yaoshi planned to pose as a traveling doctor and question remote villagers about the flower.
• Yaoshi burned his records and left the abandoned hospital for Mount Kumotori, calling the people he would meet his future patients.

Yaoshi used his reputation as a miracle doctor to search Mount Kumotori for the legendary Blue Spider Lily, and Tanjiro revealed that the flower grew beside his family’s ancestral graves. Yaoshi sent Tanjiro home with medicine for his father and planned to seek the flowers after dark, while secretly viewing Tanjiro as a specimen to dissect.

• Yaoshi treated patients in town while privately dismissing their illnesses and enduring the crowds at his free clinic.
• Tanjiro asked Yaoshi for medicine to help his ailing father.
• Yaoshi described a rare blue flower, and Tanjiro recognized it as the Azure Sky Illusion Dream near his family’s ancestral graves.
• Tanjiro told Yaoshi that the flowers bloomed at noon during the hottest days and withered when the sun began to set.
• Yaoshi gave Tanjiro medicine for his father and said he would search the mountain after dark.
• After Tanjiro left, Yaoshi revealed his greed for the Blue Spider Lily and his desire to dissect Tanjiro.

Yaoshi hid near the Kamado family grave through the day, waiting for the blue flower he believed could free him from sunlight. As the Kamado family settled into the night, Yaoshi planned to use them as test subjects after completing his perfect body.

• Yaoshi reached the grave on Mount Kumotori and hid in the shade, betting that the blue flower would bloom at noon.
• Yaoshi endured the sunlight and insects while waiting for the flower to appear and imagining himself surpassing Muzan and the other demons.
• Tanjiro returned home with free medicine from the miracle doctor and told his family about him and the blue flowers by their ancestral grave.
• The Kamado family ate dinner together, and Tanjuro quietly watched the darkness outside while Tanjiro praised the doctor.
• After the family fell asleep, Yaoshi watched their cabin and vowed to make them his first clinical test subjects.

Tanjuro met Yaoshi at a grave on Mount Kumotori, where Yaoshi searched for the legendary Blue Spider Lily. After discovering that Tanjuro had an unusual ability to see inside bodies, Yaoshi asked how he had kept his failing health under control.

• Tanjuro went out at night and used the Transparent World to see that the man standing by the grave was human.
• Yaoshi sensed Tanjuro's gaze and suppressed his urge to kill him because he still needed to find the Blue Spider Lily.
• Yaoshi introduced himself as a traveling doctor and asked why Tanjuro was outside so late.
• Yaoshi claimed he was seeking a flower that could revive the dead, and Tanjuro explained the family legend of the Azure Sky Illusion Dream.
• Yaoshi said the flower was essential to a medicine he was researching, then asked Tanjuro how he had kept his failing body from deteriorating.

Yaoshi questioned Tanjuro about his frail body and inherited breathing exercises, while Tanjuro sensed the doctor’s intense curiosity but no immediate threat. After Tanjiro joined them, Yaoshi left to seek the Azure Sky Illusion Dream, and Tanjuro went home troubled by the doctor’s unnatural control over his body.

• Yaoshi told Tanjuro that his contradictory, diseased body made him want to examine him, and Tanjuro calmly deflected his questions about his breathing exercises.
• Tanjiro arrived and happily found Tanjuro talking with the Divine Doctor, then asked whether his father had taken the medicine.
• Tanjuro thanked Yaoshi for the herbal soup, and Yaoshi said the Azure Sky Illusion Dream would be needed to cure him for good.
• Yaoshi declined Tanjiro’s offer to stay at their house and left to find somewhere nearby to spend the night.
• Tanjuro noticed Yaoshi’s heartbeat and breathing remained perfectly controlled after he vanished, then took Tanjiro home with a troubled expression.

Yaoshi hid near Tanjiro’s home on Mount Kumotori, waiting to use the family as test subjects after obtaining the Blue Spider Lily. A report identified him as a suspected Upper Rank on the mountain, and Sabito asked to fight him, but Sakonji Urokodaki refused and Shinobu Kocho suggested sending Giyu instead.

• Yaoshi endured three days of hiding in the forest while watching Tanjiro’s family and imagining turning them into test subjects.
• Sabito destroyed the training ground’s mechanical dolls with Water Breathing, Tenth Form: Constant Flux, impressing Kanae Kocho.
• Shinobu Kocho teased Sabito until a crow arrived with urgent intelligence about Yaoshi’s suspected presence on Mount Kumotori.
• Sakonji Urokodaki refused Sabito’s request to fight Yaoshi, and Shinobu Kocho recommended leaving the mission to Giyu.

Giyu Tomioka tracked Upper Rank Seven Yaoshi to Mount Kumotori and asked Tanjiro Kamado for help finding him. Tanjiro refused to believe the praised physician was a demon, while Giyu’s scent gave him no reason to think Giyu was lying.

• Giyu Tomioka reached the town and learned from the innkeeper that Yaoshi had gone up the mountain seeking the Blue Spider Lily near the Kamado family graves.
• The innkeeper told Giyu that Tanjiro Kamado might know where Yaoshi had gone, and Giyu waited for Tanjiro to arrive.
• Giyu confronted Tanjiro and asked whether he had seen the physician in a white coat.
• Tanjiro praised the physician as a kind man, but Giyu told him the physician was a demon named Yaoshi.
• Tanjiro struggled to reconcile Giyu’s warning with the physician’s clean scent and Giyu’s own scent of honesty and sorrow.

Yaoshi discovered the Blue Spider Lilies and risked crossing the deadly sunlight to eat them. Their power healed him and made sunlight nourish him, leaving him able to walk beneath the sun.

• After enduring the sunlight from the safety of the tree roots, Yaoshi watched a sea of blue flowers bloom beside the empty grave.
• Yaoshi recognized the flowers as Blue Spider Lilies and debated whether to risk reaching them in the sunlight.
• Determined to escape his fearful life and surpass Lord Muzan, Yaoshi charged from the shadows into the sun.
• As his body burned away, Yaoshi grabbed a handful of flowers and ate them without checking them first.
• The flowers restored Yaoshi's body, and he discovered that sunlight now nourished him.
• Yaoshi laughed triumphantly beneath the sun, declaring himself the one and only god who could walk in its light.

Yaoshi transformed into a demon immune to sunlight, but Tanjuro confronted him with Hinokami Kagura and severed his head. Yaoshi survived the slash and began regenerating as Tanjuro stood over him, ready to strike again.

• Yaoshi unleashed a vast demonic aura from Mount Kumotori, and Tanjiro realized it came from the divine doctor and rushed toward home.
• Giyu Tomioka sensed Yaoshi's overwhelming power and raced up the mountain to kill him.
• Tanjuro blocked Yaoshi's path and used Hinokami Kagura, causing Muzan's inherited fear to paralyze Yaoshi.
• Tanjuro decapitated Yaoshi with a flaming axe, but Yaoshi's head and body began regenerating after the golden flames went out.
• Tanjuro stomped on Yaoshi's head and said that once had not been enough.