Recaps

Chrome showed Senku the waterwheel he and Kaseki had built, but Senku recognized it immediately and asked Chen Yu to make a more advanced version. After the new waterwheel was assembled, Senku learned that Chen Yu had spent his time conscious while petrified recalling stories and entertainment, unlike Senku, who had counted the years.

• Chrome woke after nearly two hours and led Senku to the waterwheel he and Kaseki had made.
• Senku recognized the contraption as a waterwheel and asked Suika to fetch Chen Yu so he could challenge him to build a better one.
• Chen Yu gathered materials and made tools, then spent several days crafting parts for an advanced waterwheel.
• Chen Yu, Kohaku, and Magma assembled the enormous waterwheel, impressing Chrome and Kaseki.
• Senku asked Chen Yu what he had done while conscious in petrified form, and Chen Yu said he had recalled memories, novels, anime, and other entertainment.
• Senku angrily compared Chen Yu's memories of entertainment with his own years of counting in the darkness.

Senku and Chen Yu used the Waterwheel to build a hydroelectric power plant and simple batteries, while Kinro and Ginro returned from gathering iron sand. Chen Yu trained Kinro, Ginro, Kohaku, and Magma, and Senku suggested that Chen Yu had another plan for dealing with Tsukasa’s threat.

• Senku modified Chen Yu’s Waterwheel with gears and turned it into a hydroelectric power plant that generated electricity without human labor.
• Senku and Chrome collected sulfuric acid in gas masks and made five linked Simple Batteries.
• Kinro and Ginro returned after gathering iron sand, and Ginro was startled by the village’s changes before celebrating that his work was over.
• Chen Yu defeated Kinro, Ginro, Kohaku, and Magma in a training match, then woke Ginro with ammonia water and corrected the group’s mistakes.
• Gen wondered why Chen Yu did not fight Tsukasa directly, and Senku said Chen Yu likely had another idea for resolving the conflict.

Chen Yu helped the villagers make iron-plate armor for Kinro, then left to search for horses after asking Ruri about them. Kohaku took his challenge to heart and resolved to become stronger to protect Ishigami Village, and Chen Yu returned a few days later with other creatures.

• Chen Yu and the villagers finished a simple suit of linked iron-plate armor for Kinro.
• Chen Yu asked Ruri about horses, learned she had never seen one, and left the village to search on his own.
• Chen Yu refused Kohaku’s offer to accompany him, saying the four of them could not beat him, and Kohaku took out her frustration on Kinro, Ginro, and Magma.
• Kohaku realized she needed to grow stronger to protect everyone in Ishigami Village, while Kinro and Ginro began training whenever they saw her.
• Chen Yu returned to the village a few days later with other creatures.

Chen Yu brought a wolf pack and a tiger named Mimi to Ishigami Village, explaining that he had subdued them and hoped to use them as mounts. He assigned the pack to protect the village under Suika’s guidance, leaving the villagers to adjust to their new animal guards.

• Chen Yu introduced Mimi, a tiger, and Dahei, the leader of a wolf pack, startling Senku, Gen, Kohaku, and Suika.
• Senku explained what cats and dogs were to the villagers, then asked Chen Yu how he had tamed the animals.
• Chen Yu said he had beaten the wolves and Mimi into submission after finding them fighting in the woods, and described considering the wolves as mounts.
• The wolves rushed Suika and licked her until Chen Yu stopped them, revealing that they responded to her well.
• Chen Yu told Dahei and the pack to listen to Suika and guard Ishigami Village at night.

Chen Yu outfitted the wolves and Mimi with bells while the pack helped Ishigami Village stock food for winter. After hearing Hongye Yan’s report, Tsukasa grew jealous of the wolves’ gifts and went hunting for them, leading to their disappearance from the surrounding lands.

• Chen Yu and Kaseki forged bells for the fifteen wolves and Mimi, and Chen Yu fastened them around their necks.
• The wolves’ hunts increased the village’s food stores, so Kokuyo built disguised granaries to hold the surplus.
• Hongye Yan told Tsukasa that Chen Yu had tamed the wolves and a tiger, prompting Tsukasa to reassess Senku’s strength.
• Tsukasa recalled the gifts and meals Chen Yu had given him, then went hunting for wolves to punish them out of jealousy.
• Over the following years, wolves vanished from the areas around Ishigami Village and the Tsukasa Empire, except for Ishigami Village’s own pack.

Chen Yu finished preparing winter clothes, beat Ginro after Ginro mocked his bulky appearance, and finally caught Dahei stealing his grilled fish. The chapter left Chen Yu furious with Dahei after realizing he had wrongly blamed Mimi before.

• Chen Yu knitted extra layers into his coat and dressed warmly for winter.
• Ginro teased Chen Yu about looking fat, so Chen Yu beat him and left him needing four days to recover.
• Suika noticed Ginro making a victory sign while he lay bruised in bed, and the villagers suspected he had gotten out of work on purpose.
• Chen Yu baited Dahei with a grilled fish and caught him eating it.
• Chen Yu remembered that he had previously blamed Mimi for a missing fish despite Suika saying Dahei had stolen it.

Chen Yu punished Dahei and several wolves with pet cones, while Ginro’s attempt to use an iron basin as a battle standard got him chased by the pack. As Ishigami Village prepared for winter and Senku’s group worked on the Electric Light, an arrow suddenly shot toward Chen Yu.

• Chen Yu made a protective cone and fastened it around Dahei’s neck as punishment, then fitted cones on several wolves that had howled at him.
• Dahei charged into a house wall while adjusting to the cone, and the wolves divided into groups with and without cones.
• Ginro tried to provoke the wolves with Chen Yu’s iron basin, but they chased him until he escaped onto a roof; Chen Yu explained why Senku had not been attacked.
• Senku, Chrome, and Kaseki worked on the Electric Light’s vacuum component as others trained, prepared for winter, and helped finish telephone wire.
• Chen Yu found Soyuz, the heir to Treasure Island, and later an arrow suddenly shot toward him.

Chen Yu received a plea from the Tsukasa Empire to treat a seriously ill man and decided to help despite the danger. Kohaku insisted on accompanying him, and after meeting Ukyo, Chen Yu arranged for the patient to be brought to Ishigami Village while he prepared tools.

• Chen Yu dodged an arrow carrying a message that someone in the Tsukasa Empire was seriously ill and needed his help.
• Senku agreed to let Chen Yu go, while Kohaku and the others objected; Kohaku eventually decided to accompany him.
• Chen Yu caught Kohaku following him and allowed her to come along.
• Chen Yu and Kohaku met Ukyo, who explained that a man had developed a fever and begun coughing blood after a wild boar's tusk pierced his abdomen.
• Chen Yu told Ukyo to bring the patient to Ishigami Village and return to Tsukasa while he prepared tools.

Chen Yu prepared Ishigami Village to operate on a patient from the Tsukasa Empire, while Taiju, Yuzuriha, and Tsukasa arrived. The chapter ended as Chen Yu startled Ginro and drew Tsukasa’s attention.

• Chen Yu asked Ukyo to bring his assistants, Yuzuriha, and Taiju, and warned that the patient might die during surgery.
• Chen Yu returned to Ishigami Village and enlisted Senku, Kaseki, and Kokuyo to make surgical tools and build an operating room.
• Taiju and Yuzuriha arrived on the third day, and Taiju nearly suffocated Senku with an exuberant hug.
• Taiju explained that Tsukasa had come to the village himself because he worried they would not return.
• Tsukasa surveyed the villagers surrounding him while Ginro hid in fear, and Chen Yu startled Ginro, drawing Tsukasa’s attention.

Tsukasa reunited with Chen Yu in Ishigami Village and joined the preparations for a surgery that Chen Yu led with help from the others. The operation began, but the patient’s sudden cries of pain frightened the villagers waiting outside.

• Tsukasa rushed to Chen Yu, embraced him, and explained that he had come to protect Chen Yu’s assistants and friends.
• Reiko tackled Chen Yu, and he examined her after noticing how unexpectedly fast she was.
• Chen Yu assessed the patient as having a seventy percent chance of survival, reassuring Xiao Xi, Miwa, and Reiko.
• Tsukasa and Taiju built the operating room while Yuzuriha prepared supplies and Chen Yu’s helpers made surgical tools; seven days later, the setup was ready.
• Chen Yu took the patient into the operating room and began the surgery, while Senku explained surgery to the villagers outside.
• A howl of pain from the operating room startled the villagers, who began to regard Chen Yu as dangerous.

Chen Yu and his companions performed the Stone Age’s first surgery, overcoming Reiko’s mistakes and using a risky anesthetic to treat a man’s internal injuries. The patient survived and began recovering while Chen Yu rested, and the settlement turned to winter work and snow sculptures.

• Reiko forgot to inject the patient with anesthetic, so Chen Yu stopped the operation after making an incision and prepared again.
• Chen Yu and the others completed the surgery using an anesthetic mixture, and Miwa reported that the man had been asleep for about three hours and forty-five minutes.
• Chen Yu told Senku the surgery had more or less succeeded, then went to sleep and left follow-up care to Miwa and Xiao Xi.
• Miwa and Xiao Xi wheeled the awake patient out, and Tsukasa forced onlookers to back away before the man was taken to a house to recover.
• Taiju and Yuzuriha began making tools and machines, while Chen Yu used Tsukasa as a model for snow sculptures and Chrome built a sled for winter travel.

Chen Yu sculpted Tsukasa in a discus-throwing pose, prompting a discussion about the Olympic Games and the possibility of holding competitions in the future. The others speculated about Tsukasa and Chen Yu’s closeness, while Ginro’s medal-winning daydream drew Tsukasa’s murderous attention.

• Tsukasa posed for Chen Yu, who carved a snow sculpture of him dressed as a discus thrower.
• Chen Yu explained the Olympic Games to Ginro and the onlookers, and Gen compared them to their grand tournament.
• Chen Yu suggested that a larger competition between their groups might be possible in the future.
• Suika nearly voiced a theory about Tsukasa and Chen Yu’s relationship, but Kohaku covered her mouth.
• Ginro fantasized about winning medals and charming the village girls, so Tsukasa turned a murderous gaze on him.

Chen Yu encouraged Tsukasa as Senku’s treatment stabilized the injured man, while a woman revived in America searched for a token declaring war. Back in Ishigami Village, Chen Yu taught Ruri and the others about medicinal plants and asked Ruri to help him remember the past.

• Tsukasa read Reiko’s report that the injured man was stable, and Chen Yu told him not to seek out Reiko.
• Chen Yu reminded Tsukasa that things could improve, and Tsukasa trusted his promise that a miracle might be possible.
• In America, a revived woman dislocated a man’s arm, stabbed his thigh, and took clothing Xeno offered her.
• The woman dressed and searched for the war token someone had given her.
• Chen Yu taught Ishigami Village residents to identify herbs, and Ruri recalled that some were already recorded in the Hundred Tales.
• Chen Yu asked Ruri to help refresh his memory because he had forgotten parts of the past.

Lilith recalled her long rivalry and growing affection for Chen Yu, whose medical breakthroughs she had tried to shield him from danger. Thousands of years later, she found a surviving gift from him and resolved to beat him someday.

• At an international medical presentation, Chen Yu unveiled an inexpensive treatment, and Lilith angrily confronted him over the danger his announcement could bring.
• Chen Yu insisted he would continue trying to reform medicine, while Lilith tried to protect him by challenging his discoveries and pointing out possible side effects.
• After Lilith fell ill, Chen Yu sent her a longevity lock pendant and a message reassuring her; they continued their verbal battles as he pursued medical research.
• When Chen Yu became harder to meet, Lilith missed him, took up martial arts after hearing he liked them, and began carrying his pendant close as her feelings changed.
• In a world thousands of years in the future, Lilith found the surviving pendant, and Xeno remembered her rivalry with Chen Yu.
• Chen Yu said Lilith had missed her chance to beat him and could no longer defeat him.

Chen Yu struggled to calculate when Lunar New Year would fall, and Senku told him it was still a month away. After Gen discussed a birthday present for Chen Yu, Chen Yu decided to prepare a gift for Senku as well, and he and Gen secretly finished making it.

• Chen Yu spent days covering papers with calculations as he tried to work out when Lunar New Year would arrive.
• Senku recognized what Chen Yu was calculating and reassured him that Lunar New Year was still a month away.
• Senku explained Lunar New Year to Chrome, who had not understood the holiday.
• Gen told Chen Yu he wanted to give him a birthday present, prompting Chen Yu to remember he had not prepared Senku's gift.
• Chen Yu and Gen secretly made a precise birthday present for Senku and finished it within a few days.

Chen Yu and Gen arranged a surprise gathering for Senku, unveiling Chen Yu’s astronomical telescope and fireworks. Gen revealed that the celebration was also meant to welcome the New Year and give Chen Yu a gift, leaving Chen Yu and Senku sharing the villagers’ good wishes.

• Senku, Chrome, and Magma set off to explore the mine while Gen stayed behind to help Chen Yu organize a surprise.
• Five days later, Chen Yu prepared the astronomical telescope at the observatory and waited with the villagers for Senku’s return.
• The villagers blindfolded Senku and revealed Chen Yu’s telescope, which Senku examined as he recalled his childhood.
• Gen launched fireworks and explained that he had arranged the gifts for Chen Yu and Senku together.
• Gen and the villagers wished Chen Yu a Happy New Year, and Senku learned that the celebration included a birthday gift for him.

Chen Yu spent two months secretly building a powerful weapon and emerged with a heavy black stick that Senku recognized as a flintlock. Senku took charge of the firearm while the group wondered whether Chen Yu had also made ammunition.

• After the fireworks, Chen Yu surveyed the launch site and decided to develop a weapon using blueprints he drew the next day.
• Chen Yu gave the blueprints to Senku and old Kaseki, and Senku agreed to make the parts despite not understanding some of them.
• Over the next two months, Chen Yu repeatedly revised his design in a secret base until he completed the weapon.
• Chen Yu tossed the heavy black weapon to Senku and went to sleep, leaving Senku sprawled on the ground from its weight.
• Gen brought Senku another black object, and Senku recognized it as a flintlock, warned everyone not to touch it, and kept it for safekeeping.

After recovering from his exhaustion, Chen Yu went to Chrome’s hut, where Senku and the others were testing armor and paper shields. He sparred with Kinro and pointed out missed counterattack chances, leaving Kinro dejected.

• Chen Yu woke at noon, checked his weapon and the well-maintained Sword Box, then headed to Chrome’s hut.
• Senku explained that the group was comparing the protection of paper shields and Chen Yu’s armor, and Kohaku, Magma, and Kinro described their tests.
• Chen Yu asked for a sparring partner, and Kinro stepped forward to test how much he had improved.
• Chen Yu defeated Kinro with quick staff strikes and explained two opportunities Kinro had missed to counterattack.

Chen Yu explained why mastering one technique through repetition could make Kinro’s Tube Spear Style formidable, then praised a kung fu legend as stronger than Tsukasa. The group reflected on the legend’s early death, while Kohaku briefly imagined becoming strong enough to defeat Chen Yu.

• Kinro showed Chen Yu the Tube Spear Style he had learned and asked for feedback on his improvement.
• Chen Yu called the technique introductory and explained that repeatedly practicing one move could make it powerful.
• Chen Yu quoted a kung fu master, prompting Gen to recognize the words as belonging to an international martial arts superstar.
• Chen Yu described the superstar’s accomplishments and declared that he would have beaten Tsukasa hands down.
• Kohaku mourned the master’s early death and wondered whether she could someday become strong enough to beat Chen Yu.

Chen Yu demonstrated several spear styles to the villagers, and Kinro chose to learn the Qi Family Spear. Chen Yu challenged him to survive against him or defeat him before he would teach it.

• Chen Yu demonstrated the seven routines of the Yang Family Spear and told Kinro that spear techniques should be used to protect people.
• Kinro asked to learn, and Chen Yu said he would need to become his disciple and choose a suitable style.
• Chen Yu demonstrated portions of the Zhao Family Spear, Yue Family Spear, and Qi Family Spear, whose display frightened Kohaku and Magma.
• Senku explained that Ginro had fainted and Suika had taken him to rest with help from someone else.
• Kinro chose the Qi Family Spear, and Chen Yu demanded that he survive against him or defeat him to earn the chance to learn it.

Kinro chose the Qi Family Spear and began training under Chen Yu, while Chen Yu and Senku built a hand-cranked Warning Horn. Hongye Yan watched from afar, still anxious after mistaking the earlier fireworks for firearms.

• Kinro lost every spear match against Chen Yu, who agreed to teach him basic techniques if he could eventually win.
• Senku and Gen warned the others not to interfere with Chen Yu’s decision or probe too deeply into the history behind the Qi Family Spear.
• Chen Yu asked Senku to help make a hand-cranked Warning Horn, and they completed it after three days of assembly and adjustments.
• Chen Yu tested the horn, but Hongye Yan watched from a distance and could not identify the brief, loud sound.
• Hongye Yan recalled how she had mistaken the fireworks for firearms and alarmed Tsukasa’s Empire before Ukyo and Tsukasa clarified what they were.
• Hongye Yan remained frustrated and anxious as she watched Chen Yu and the others gather.

Chen Yu found two bottles of Revival Fluid and prepared to revive Tsukasa’s younger sister, Mirai, before the coming battle. He left Senku to guard the village and set off with Suika to find her.

• Tsukasa sent Ukyo and Hongye Yan on a reconnaissance mission to investigate Chen Yu’s new weapon.
• Chen Yu told Senku that Tsukasa’s empire might eventually turn against him if he failed to meet the people’s needs, and planned to use Mirai to gain Tsukasa’s cooperation.
• Chen Yu searched the place where Tsukasa and the others had worked and dug up two bottles of Revival Fluid hidden beneath a board.
• Chen Yu asked Senku to guard the village and prepare for an enemy attack while he went to revive Mirai.
• Chen Yu recruited Suika to accompany him and gathered clothes for Mirai’s revival.

Chen Yu and Suika searched for the hospital site for days, enduring a wolf attack before Chen Yu found Mirai's statue. Chen Yu revived Mirai, but as he watched her emerge from the tent, he worried that people would no longer need him once they had a Petrification Weapon.

• Chen Yu and Suika used his memories and map to locate a clearing where the hospital might have stood, then began digging.
• After several days of searching, Chen Yu fought off a pack of wolves while Suika stayed in their tent, where a wolf broke in and was killed by Chen Yu's spear.
• Chen Yu butchered the wolves, reinforced the tent, and kept watch while Suika slept.
• Chen Yu found Mirai's statue, dressed her in one garment, and poured Revival Fluid over her.
• Mirai revived and stepped outside with Suika, while Chen Yu felt glad for Tsukasa but worried that the Petrification Weapon would make him unnecessary.

Chen Yu returned to Ishigami Village with Mirai and Suika, then tested the villagers by attacking them in the dark and nearly striking Senku. After revealing his voice imitation and explaining the ambush, he prepared to review the villagers’ mistakes.

• Chen Yu brought Mirai and Suika back to Ishigami Village around one in the morning, carrying wolf pelts and other spoils.
• Ginro mistook the bloodstained Chen Yu for an enemy, so Chen Yu cut the Electric Light’s wire and attacked the villagers in the darkness.
• Chen Yu quickly defeated Ginro, Kinro, Kohaku, Magma, and others, then charged at Senku while Gen warned Kohaku.
• Kohaku intervened, but Chen Yu caught her kick and threw her aside before a light let Senku recognize him.
• Chen Yu imitated Tsukasa’s voice and threatened Senku with his spear, then revealed Suika and Mirai and explained his voice imitation.
• Chen Yu told the villagers they had failed to handle a sudden attack and began addressing their mistakes.

Chen Yu assessed the fighters’ weaknesses and proposed ways to improve their combat roles, then hinted that his side had a plan to end the war soon. Ukyo collapsed after inhaling a fragrance and was discovered by Chen Yu and the others.

• Chen Yu told Kohaku to improve her lower-body balance, advised Kinro to guard his back and practice spearmanship, and suggested Magma use armor or throw stones.
• Chen Yu gave the group cold-prevention pills and assigned roles, identifying Senku as a scientist and Gen as a deceiver suited to diplomacy.
• Chen Yu told Senku that the battle would end within three months and said he had a plan when Kinro asked whether they could win.
• Ukyo decided not to report Chen Yu’s intelligence to Tsukasa, but collapsed after realizing he had inhaled a strange fragrance.
• Chen Yu and the others arrived where Ukyo had fallen.