Chapter Summaries

Chen Yu returned to Tsukasa’s camp with medicinal herbs, gave Tsukasa protective armor, and asked for help finding medical assistants. While Tsukasa was away, Hyoga tried to recruit Chen Yu by explaining his belief in eliminating the weak.

• Chen Yu showed Ukyo the pharmacy and asked Taiju and Yuzuriha to make life-size stone statues from memory.
• Chen Yu reached Tsukasa’s headquarters, where Tsukasa released Gen after Chen Yu confirmed the trip had gone well.
• Chen Yu gave Tsukasa the concealed armor Taiju and Yuzuriha had made and asked him to find two or three people with medical knowledge.
• Hyoga approached Chen Yu while Tsukasa was away and asked him to join forces.
• Hyoga said he wanted to eliminate the weak and needed Chen Yu’s help identifying people who only appeared strong.

Chen Yu recruited women to assist with medical work as Tsukasa and Minami Hokutozai brought him three candidates. He examined Shiraishi Koki’s congenital throat condition, leaving her fate uncertain after saying it would be troublesome to treat.

• Chen Yu refused Hyoga’s invitation to join the war and asked Tsukasa to find women skilled in medicine to work as his assistants.
• Tsukasa brought reporter Minami Hokutozai, and Chen Yu scolded Tsukasa after learning that nightclub workers had asked him for contraceptive medicine.
• Minami Hokutozai returned with three women she had rescued from being disposed of: Suzuki Reiko, Kitano Miwa, and medical intern Shiraishi Koki.
• Suzuki Reiko excitedly recognized Chen Yu as her idol, and he explained that he needed help managing medicinal herbs.
• Chen Yu examined Shiraishi Koki’s wrist after learning she could barely speak, then said her long-standing condition would be troublesome to treat.

Chen Yu treated Xiao Xi’s speech condition and protected her and the other women after a man harassed her. He asked Ukyo to watch over the Medical Team, but Ukyo refused, leaving their safety uncertain.

• Chen Yu told Xiao Xi her condition could be treated and ordered her to limit her speech while treatment began.
• Chen Yu brought Reiko, Miwa, and Xiao Xi to examine the injured, warning them to seek protection if anyone threatened them.
• Chen Yu caught a man groping Xiao Xi, dragged him to the infirmary, and punished him with bone needles until he begged for mercy.
• The Tsukasa Empire’s Medical Team was officially established, and Chen Yu’s reputation deterred people from mistreating its members.
• Chen Yu asked Ukyo to protect the three women if they called for help, especially the nonspeaking Xiao Xi, but Ukyo refused.

Chen Yu reprimanded Reiko for repeatedly mishandling herbs, then examined Xiao Xi and found that her recovery was progressing well. He later treated Tsukasa’s injury, asked him to store extra Revival Fluid, and joined him in planning a barbecue to celebrate his lion hunt.

• Chen Yu scolded Reiko for gathering dangerous herbs and sent her to dry the herbs after Xiao Xi stopped him from berating her further.
• Chen Yu examined Xiao Xi, adjusted her prescription, and told her she should be almost recovered by next year.
• Chen Yu found Tsukasa returning with a lion and treated the injury Tsukasa had tried to hide.
• Chen Yu told Tsukasa to rest his arm, use the medicine daily, and hide extra portions of Revival Fluid in the cave.
• Chen Yu invited Tsukasa to a barbecue celebrating his lion hunt, joking that he had become a great tribal warrior.

Chen Yu brought Reiko and Miwa to gather herbs, then tested their willingness to support a plan to restore civilization and revealed his secret. The group reached Senku’s experimental site, where Chen Yu introduced the two women as future medical support and asked whether the cola was ready.

• Chen Yu went down the mountain with Reiko, Miwa, and Gen to gather medicinal herbs, and Miwa asked for a metal dagger with a specific shape.
• Chen Yu asked Reiko and Miwa whether they would support restoring civilization, and both agreed to keep his plans secret and help him.
• Chen Yu told Gen that Tsukasa and Senku’s conflict might be decided by one battle and that he needed to win over Kirisame and Mozu.
• Chen Yu and the others arrived at Senku’s experimental site, where Chen Yu introduced Reiko and Miwa as future medical support and explained Miwa’s condition for helping.
• Chen Yu asked Senku whether the cola was ready, hoping it could help draw people from the Tsukasa Empire to their side.

Senku recruited Kaseki to make glass bottles, while Chen Yu advised Senku about treating Ruri and let him continue pursuing the medicine needed to win over Ishigami Village. As Kinro and Ginro trained to stop Magma from marrying Ruri, Kinro refused Chen Yu’s offer of treatment.

• Senku baited the bound Kaseki with glasswork, and Kaseki broke free and began making bottles with skill.
• Kaseki and the others worked through the night to produce enough glass containers, and Chen Yu told Miwa that her dagger could be made.
• Senku asked whether herbal medicine could replace sulfonamide drugs, and Chen Yu said it might help Ruri but urged him to make the drug quickly.
• Over the next few days, Kaseki made containers while Kinro and Ginro trained and the group generated electricity.
• Chen Yu warned Kinro that his muscles were overworked, but Kinro refused treatment because he wanted to stop Magma from marrying Ruri.

Miwa remembered her loving childhood with her father and the killers who destroyed their home, fueling her long pursuit of revenge. After Chen Yu noticed her killing intent and unusual fighting stance, he disarmed and restrained her, then asked what was going on.

• Kaseki and Miwa completed an iron dagger, which brought Miwa to tears as she remembered her father.
• Young Miwa practiced with a dagger despite preferring to become a doctor, and her father reassured her that he would protect her.
• Miwa returned home to find her father badly wounded, and he hid her with a dagger while killers searched and burned down their house.
• Miwa entered an orphanage, later trained for revenge, and learned after her revival that she could bring her father back.
• Chen Yu noticed Miwa's killing intent, and Senku distracted her so Chen Yu could disarm and restrain her.
• Chen Yu asked Miwa what she was after and why she had hidden who she was.

Chen Yu used strange acupuncture techniques to make the captured Miwa talk. After he and Kaseki crafted fine needles and Chen Yu treated Kaseki, Miwa confessed to everything, though the chapter did not reveal what she said.

• Chen Yu tied up Miwa and tried to intimidate her with a bone needle, while Senku recognized that Chen Yu planned to have Kaseki build a sword box.
• Chen Yu convinced Kaseki to make the device in exchange for plans, and Senku warned that it could be devastating for their Stone Age civilization.
• Chen Yu, Kaseki, and Kohaku made seven iron needles and two silver needles, and Chen Yu used some to give Kaseki acupuncture treatments.
• Chen Yu inserted needles into Miwa, temporarily paralyzing her and then causing alternating cold and heat and dizziness until she agreed to talk.
• Chen Yu removed the needles, and Miwa gave a full account of everything.

Chen Yu demonstrated the Tube Spear Style and Return Horse Spear, then trained with Kohaku while Kinro studied the techniques. The next day, Kinro began imitating Chen Yu's moves during practice, while Chen Yu continued sparring with Kohaku.

• Miwa finished recounting her story, and Chen Yu argued against killing her because her disappearance would draw suspicion from the Tsukasa Empire.
• Chen Yu demonstrated Hyoga's Tube Spear Style with Ginro's spear and invited Kohaku to spar so Kinro could study the technique.
• Chen Yu used a Return Horse Spear to catch Kohaku off guard and knock her down, then asked Miwa whether she wanted revenge.
• The next day, Reiko and Miwa gathered medicinal herbs, Senku and Chrome researched, and Kaseki worked on Chen Yu's sword case.
• Kinro began imitating Chen Yu's spear techniques while training with Ginro, and Chen Yu continued knocking Kohaku down during their sparring.

Chen Yu taught Kohaku to hold a horse stance and tested a sword case Kaseki had forged, then demonstrated his swordsmanship to the others. He refused to take on a combat role, insisting he would remain support.

• Kohaku asked Chen Yu to teach her, and he had her hold a horse stance while Ginro tried to provoke her.
• Miwa asked about training, and Chen Yu told her she had already built her foundation before she returned to helping Reiko with herbs.
• Kaseki showed Chen Yu a sword case and three swords, and Chen Yu approved of his work and encouraged him to forge a sword of his own.
• Chen Yu tested the sword case, demonstrated his swordsmanship, and told Kohaku that close-quarters combat would suit her better than his sword techniques.
• Chrome wondered whether Chen Yu could handle Long-Haired Man or Hyoga, but Chen Yu declared he would only provide support and logistics.

Chen Yu rescued Ginro from a deadly lake and devised a way to collect its poisonous water. The group left with the water and planned to make gas masks so they would not have to depend on Chen Yu.

• Chen Yu hid the sword, learned that Senku and the others had gone to gather ingredients, and hurried after them with medical supplies.
• Chen Yu warned Kohaku to pull Ginro back from the lake, where birds dissolved in the water and Ginro had become trapped in a frightening illusion.
• Chen Yu examined Ginro and explained that the illusion had captivated him, then used acupuncture to calm him.
• Chen Yu protected himself with needles and collected the lake water in a glass bottle using a rope and a falling column of water.
• Chen Yu warned the others to stay away from the lake, while Senku said they needed to make gas masks; Kohaku and Chrome carried the sleeping Ginro back.

Chen Yu gathered poisonous gelsemium and processed it into Paralysis Powder, using Senku as an unwilling test subject. Senku woke furious and vowed to get revenge once he restored society.

• Chen Yu found gelsemium near Ishigami Village, dug up the plant, and brought it back despite Kohaku's warnings.
• Chen Yu processed the poisonous plant and dried it away from the work area after Senku and Chrome objected.
• Chen Yu gathered and ground herbs, then made a packet of Paralysis Powder the next day.
• Chen Yu sprinkled the powder on Senku, who lost sensation and slept until evening before realizing he had been used as a test subject.
• Senku confronted Chen Yu, but Chen Yu knocked him out; the next day, Kohaku and Chrome stopped Senku from retaliating, and Chen Yu worked for him for a day.

Chen Yu questioned his purpose in the Stone World, and Senku encouraged him to use his medical knowledge as part of a special action team. Chen Yu and Gen left to carry out their mission, while Ishigami Village prepared for its tournament.

• Gen asked Senku whether making Chen Yu work would harm his hands, and Senku pointed out Reiko and Miwa as other available helpers.
• Chen Yu tried to make a mold but gave up when the work proved beyond his skills.
• Chen Yu asked Senku whether reviving humanity still mattered and what purpose he had in the Stone World.
• Senku reminded Chen Yu that he had revived him to help keep Tsukasa in check and offered him the role of leader of a Biochemical Weapons Action Team.
• Chen Yu gave Gen a dagger and handed Senku his Paralysis Powder before he and Gen left on their mission.
• After Chen Yu and Gen left, Ishigami Village's tournament began.

Chen Yu returned to the Tsukasa Empire, cared for Xiao Xi, and prepared medicines while discussing the empire’s needs with Tsukasa. As they worked, Chen Yu explained why he wanted to pass down traditional Chinese medicine, while Senku entered the grand tournament in Ishigami Village.

• Chen Yu returned to the Tsukasa Empire, checked Xiao Xi’s recovery, and told her to rest.
• Chen Yu sorted and labeled herbs with Miwa and Reiko, then prepared medicinal powders for later use.
• Tsukasa told Chen Yu that Hyoga and the others had found the village at the foot of the mountain and planned to investigate it.
• Chen Yu asked Tsukasa about the empire’s population and urged him to assign people to help make warm clothing for winter.
• Chen Yu explained that he had focused on traditional Chinese medicine because it was easier to pass down, and Tsukasa silently resolved to help him preserve it.
• Senku entered the grand tournament in Ishigami Village as the others watched in astonishment.

Chen Yu organized preparations for the Tsukasa Empire’s future food supply while Hyoga took Gen to Ishigami Village, where Senku had become chief. At the Grand Bout, Magma fought to show how he had changed, and Senku defeated Ginro with a precise strike using Suika’s watermelon helmet.

• Chen Yu arranged for people to hunt and smoke meat, prepared land for farming, and planned to explore and map the changed landscape.
• Hyoga tried to abduct Miwa or Reiko, but Chen Yu caught the gymnast and punished her with Itching Powder before Hyoga took Gen to Ishigami Village.
• Magma entered the Grand Bout to prove he had changed, defeated Kinro through strength, and fought alongside Chrome for the chief’s position.
• Ginro misunderstood a rumor about Ruri and attacked Senku in earnest, alarming the villagers who feared he might become chief.
• Senku used Suika’s damaged watermelon helmet to trap Ginro’s staff and struck him down.

Senku won the village chief duel after Chrome fell asleep, but he rejected the marriage to Ruri so he could focus on making the Special Medicine. As Senku and Kohaku left to prepare it, Gen hurried to warn them that Hyoga was coming.

• Chrome fell asleep after exhausting himself in his contest with Magma, so the referee declared Senku the winner of the Imperial Duel.
• Senku agreed to marry Ruri, then learned that Chen Yu’s herbs had improved her health and that she no longer appeared critically ill.
• Kokuyo objected to Senku becoming chief, but Senku ignored him and demanded alcohol after the duel.
• Senku abruptly announced that he and Ruri should get divorced, then left with Kaseki to make the Special Medicine while Kohaku carried the alcohol and vinegar after them.
• Kinro and Ginro explained to Kokuyo what they had been doing, calming him, and Gen ran to warn Senku that Hyoga would soon arrive and that he had sabotaged Hyoga’s weapon.

Senku completed the medicine for Ruri, who recovered and became chief Senku’s link to a mystery about his name and Chen Yu. Far away, Chen Yu remembered a song and saw the faces of people from the space station, including a woman who sang.

• Gen helped Kaseki with experiments, then later found and drank the cola Senku had made.
• Senku, Chrome, and the others completed the medicine, and Kohaku brought it to Ruri.
• Senku examined Ruri and confirmed her illness had affected her lungs, while Ruri began coughing after taking the medicine.
• Ruri’s breathing improved, and she recovered enough to run; Kokuyo then announced Senku as Ishigami Village’s chief.
• Ruri told Senku that she had known his name, Senku Ishigami, and Chen Yu’s name since the distant past.
• Chen Yu remembered a lonely song and saw the faces of the people aboard Earth’s space station, including a woman who sang.

Chen Yu unexpectedly traveled to the space station during the petrification event and told Byakuya Ishigami and the others about humanity’s future. After the encounter vanished from everyone else’s memories, Chen Yu returned to his own time with Lillian’s song remembered, intending to share it with future generations.

• Chen Yu appeared on the space station, where Byakuya Ishigami and the others learned that Earth had been petrified.
• Chen Yu explained that he had come from 3,700 years in the future, described Senku’s work and their descendants, and told Byakuya that Senku was doing well.
• At Chen Yu’s request, Lillian sang, and Chen Yu memorized her song before telling the group about Ishigami Village and their descendants.
• Chen Yu disappeared, and everyone except Byakuya forgot meeting him; Byakuya wrote down the encounter and urged himself to remember Chen Yu.
• Chen Yu returned to his own time, remembered Lillian’s song, and ran down the mountain with Xiao Xi, Reiko, and Miwa to sing it for future generations.

Chen Yu and Reiko sang a song of hope that reached both the Tsukasa Empire and Ishigami Village, lifting the spirits of those who heard it. After returning safely to Tsukasa, Chen Yu wondered whether tomorrow would be better.

• Tsukasa learned that Chen Yu had left with the women and sent people after them, including a muscular blonde woman.
• Chen Yu brought Miwa, Xiao Xi, and Reiko to a hill and asked them to sing; he and Reiko performed a song inspired by Lillian.
• The people following Chen Yu were moved by the song, while Senku, Kohaku, Ruri, Suika, and Chrome heard it from Ishigami Village and felt hopeful.
• After Senku explained that he and Byakuya were not related by blood, Magma repeatedly jumped into the sea in frustration.
• Chen Yu returned to the Tsukasa Empire, where Tsukasa praised his singing and joined him for grilled meat.

Chen Yu treated a flood of patients in the Tsukasa Empire with medicinal herbs and acupuncture, then treated Tsukasa for a chill. The exhausted Reiko nearly poisoned herself by chewing on Pokeweed, and Chen Yu caught her in the act.

• After Chen Yu's song stirred up pent-up emotions, injured, ill, and sleepless people overwhelmed the Tsukasa Empire's four doctors.
• Chen Yu examined patients and directed Miwa, Reiko, and others to prepare herbal remedies for a range of ailments.
• Chen Yu treated patients through the day and into the night, using bone needles for acupuncture when herbs were unavailable.
• Tsukasa visited Chen Yu, who noticed he had caught a chill and made him drink a bowl of soup.
• Chen Yu discovered that sleeping Reiko was chewing on stored Pokeweed, snatched it from her, and scolded her.