Chapter Summaries

After dying from an illness, Chen Yu was reborn into a wealthy family and devoted himself to studying medicine and martial arts. His parents took him to Japan for a vacation, and he looked out toward the island as their plane neared its destination.

• Chen Yu died of his illness after wishing for a healthy body and the chance to study medicine and save people.
• After being reborn, Chen Yu learned quickly, studied medicine from a young age, and began practicing martial arts.
• Chen Yu's parents took him to Japan under the pretext of a business trip so he could experience life beyond home.
• On the plane, Chen Yu identified a dangerous medicine interaction in a quiz on his father's tablet.
• Chen Yu stayed awake beneath his blanket and looked out toward the island as the plane approached.

After meeting Tsukasa Shishio on a beach, Chen Yu helped him find treatment for his sick little sister and became his friend. Over the following years, Chen Yu built a reputation as a medical expert, hoping to be useful when the world of petrification came.

• Chen Yu returned his father's secret cash, accepted money and a bank card from his mother, and trained before going to sleep.
• At the beach, Chen Yu intervened when a man beat Tsukasa Shishio for collecting seashells and learned that Tsukasa had no home and only his little sister.
• Chen Yu offered Tsukasa money and promised to find his sister's hospital, then arranged a taxi for him.
• After searching hospitals with his parents, Chen Yu found Tsukasa and his sister, called Tsukasa his friend, and paid to begin her treatment.
• Before leaving the island nation, Chen Yu told Tsukasa he had studied medicine to cure his sister, and Tsukasa smiled at him.
• Over the following years, Chen Yu studied medicine and pharmaceuticals, published effective research, and gained a reputation he hoped would help him get revived after petrification.

After transferring to Senku’s school, Chen Yu tried to cure Senku’s obsession with science by testing drugs on him, but only made him resistant to them. Chen Yu stayed close to Tsukasa and his sister while waiting for the coming petrification, and grew angry at the island nation’s authorities.

• Chen Yu transferred to Senku’s school and called Senku sick for his intense devotion to science.
• Chen Yu secretly gave Senku a homemade drug and later repeatedly tested medicines on him, causing Senku to develop drug resistance.
• Chen Yu explained that he had wanted Senku to take fewer risks and prioritize staying alive, then ended his experiments.
• Chen Yu remained by Tsukasa Shishio’s side, paid for Tsukasa’s sister’s treatment, and kept her company while Tsukasa boxed at night.
• Chen Yu refused the school’s invitation to join it, telling them a world-changing miracle would happen later.
• The island nation’s authorities pressured Chen Yu until his home country intervened, and Chen Yu vowed to destroy their statues after the world was petrified.

Chen Yu anticipated the petrification, stayed conscious through the 3,700 years, and revived alongside Senku, Taiju, and Tsukasa on the island. He denied knowing the cause of the petrification and set out to find herbs for Tsukasa’s wounds.

• Chen Yu left Senku and Taiju before the green light spread, sent Tsukasa a message, and waited alone as the petrification beam approached.
• Tsukasa ran toward the school after seeing the light and was petrified, while Taiju protected Yuzuriha and Senku was petrified as well.
• Chen Yu remained conscious inside his stone body for thousands of years, reviewing memories until his awareness faded.
• After 3,700 years, Chen Yu revived and reunited with Senku, Taiju, and Tsukasa, who pulled him into a hug.
• Senku explained that the strange light had petrified humanity and swallows, and Chen Yu said he did not know its cause.
• Chen Yu examined Tsukasa’s claw wounds, told him to stay behind, and went to find medicinal herbs.

Chen Yu helped Senku and Taiju treat Tsukasa’s wound, while Senku secretly prepared to revive Yuzuriha before Tsukasa returned. Senku acknowledged that Tsukasa’s vision clashed with his own and asked Chen Yu, his future ally, about the petrification.

• Chen Yu treated Tsukasa’s wound with herbs and leaves, and Senku said Yuzuriha could make proper cloth.
• Senku sent Tsukasa to the Miracle Cave for ingredients, then revealed to Taiju that he had brought enough supplies to make revival fluid and wanted Tsukasa out of the way.
• Senku told Taiju that Tsukasa’s vision of a world ruled by the strongest made him an enemy, while Senku wanted to rebuild civilization.
• Senku questioned Chen Yu about leaving before the petrification, and Chen Yu said he had gone to visit Tsukasa’s sister in the hospital.
• Chen Yu said he was Senku’s ally and warned that Senku and Tsukasa’s opposing ideals could spark a war; Senku said he was counting on his future ally.

Chen Yu helped Senku revive Yuzuriha, then refused to choose a side in the coming fight and urged the others to trick Tsukasa into believing Senku was dead. When Tsukasa arrived, Chen Yu collapsed after taking bitter herbs, and Tsukasa mistook his action for an attempt to avoid the conflict.

• Chen Yu asked Senku to make silver acupuncture needles while the group hurried to revive Yuzuriha before Tsukasa returned.
• Tsukasa placed a shell necklace on a young girl, crushed the statues of the elderly, and left.
• Chen Yu poured revival fluid over Yuzuriha, who awoke and reunited with Taiju.
• Senku asked the group to choose between fleeing and fighting Tsukasa; Taiju and Yuzuriha chose to fight, while Chen Yu refused to take sides.
• Chen Yu examined Senku, Taiju, and Yuzuriha, warned them that Taiju was in the greatest danger, and told them to fool Tsukasa into thinking Senku was dead.
• Chen Yu collapsed after swallowing herbs as Tsukasa arrived; Senku shouted for the others to run, while Tsukasa stayed behind and decided to use gentler methods against Chen Yu.

Tsukasa spared Senku, Taiju, and Yuzuriha because of Chen Yu, then left to destroy the statues he considered useless and establish a new order. Senku decided to create a weapon of civilization that could threaten Tsukasa, while Taiju remembered how Chen Yu had once used him as an anatomical model.

• Tsukasa tracked Senku, Taiju, and Yuzuriha, and Senku’s arrow and Taiju’s attack failed to stop him.
• Taiju collapsed after Tsukasa’s kick, and Senku told Yuzuriha that Taiju would be out for days.
• Tsukasa let Senku and Yuzuriha go for Chen Yu’s sake and warned that he would kill them if they became his enemies.
• After Tsukasa left, Taiju admitted that he might really be injured, and Senku explained Tsukasa’s plan to destroy statues and establish a new order.
• Taiju recalled that Chen Yu had used him as an anatomical model, and Senku proposed making a weapon of civilization to threaten Tsukasa.

Chen Yu kept Tsukasa away while Senku, Taiju, and Yuzuriha raided the Laboratory for materials, then encouraged Tsukasa to pursue his plan while betting that Senku was right. The chapter left Chen Yu alone at the Laboratory, considering the people and specialists he remembered.

• Senku smashed the clay pots to make it look as if he and Taiju and Yuzuriha had fled in fear of Tsukasa.
• Chen Yu woke in the Laboratory, and Tsukasa freed him before the two went for a walk.
• Senku, Taiju, and Yuzuriha reached the Laboratory after Chen Yu and Tsukasa left and collected the supplies they needed.
• Chen Yu asked Tsukasa to reconsider his plan and proposed a bet that Senku was right, which Tsukasa accepted.
• Chen Yu and Tsukasa returned to the Laboratory, where Chen Yu realized Senku had taken materials to make a weapon against Tsukasa.
• Tsukasa left to pursue Senku while Chen Yu stayed behind and thought about the strengths of people he remembered.

Chen Yu encountered Kohaku and gave her instructions for medicine before leaving to search for the Miracle Cave. Tsukasa killed Senku, but Taiju and Yuzuriha revived him with the revival fluid, and Senku awoke to Chen Yu’s mocking narration of his survival efforts.

• Chen Yu met Kohaku in the forest, identified herbs for her sick sister, and left to search for the Miracle Cave.
• Tsukasa struck Senku down, and Yuzuriha and Taiju arrived to witness his apparent death.
• Taiju lifted and threw a huge rock while Yuzuriha threw a jar of gunpowder at Tsukasa, setting off an explosion that let them escape.
• Taiju found the revival fluid in his backpack and poured it over Senku, whose petrification began to break.
• Senku regained consciousness and heard Chen Yu joking about his efforts to survive among the monkeys.

Senku awakened after Taiju and Yuzuriha followed Chen Yu’s advice, and the three prepared to move forward. Meanwhile, Chen Yu urged Tsukasa to begin reviving people, and Tsukasa went to the Miracle Cave to start his plan.

• Taiju and Yuzuriha waited for Senku to awaken after the storm ended, and Senku spoke to them from the ground.
• Senku learned that Chen Yu had guided Taiju and Yuzuriha, then Yuzuriha fastened a makeshift brace around his neck.
• Chen Yu gave Tsukasa dry clothes and asked what he intended to do after killing Senku.
• Tsukasa declared that he would purge the parasites of humanity, and Chen Yu warned that rebuilding civilization without Senku would be difficult.
• Chen Yu told Tsukasa to revive people for examination, and Tsukasa headed to the Miracle Cave to prepare the revival mixture.

Chen Yu helped Tsukasa’s growing empire revive new people and trained its members, while Senku and Kohaku discussed the herbs Chen Yu had provided. As Gen’s persistent questions wore Chen Yu down, Gen finally raised the subject of Senku, Tsukasa’s supposed enemy.

• Taiju and Yuzuriha arrived at Chen Yu’s settlement, where Chen Yu put them to work mixing revival fluid and repairing a backpack.
• Chen Yu explained his close bond with Tsukasa, and the group settled in together; Tsukasa later revived a reporter and several other admirers with Chen Yu’s revival fluid.
• Senku recognized Chen Yu as the doctor who had treated him and urged Kohaku to follow Chen Yu’s instructions for her sister’s medicine.
• Tsukasa’s empire grew and revived Hyoga, while Chen Yu examined Tsukasa and prepared under-armor for him.
• Chen Yu taught the settlers to hunt, butcher animals, and treat injuries, but his harsh lessons gave Taiju and Yuzuriha a frightening reputation.
• Gen repeatedly pestered Chen Yu with questions, then said they should discuss Senku, Tsukasa’s supposed enemy.

Chen Yu accompanied Gen to Ishigami Village to investigate the strange person and modern supplies Gen had spotted, where they found Senku alive. Senku recognized Chen Yu and Gen, then joked that Chen Yu might be carrying poison, alarming Gen and the villagers; he reassured Kohaku that Chen Yu’s medicine was safe.

• Gen told Chen Yu he suspected Senku was alive and described a village where he had seen someone strange and things from the modern world.
• Chen Yu left a message for Tsukasa and went with Gen toward Ishigami Village, while Tsukasa reacted angrily when he learned they had gone together.
• Chen Yu and Gen reached the village and found Senku serving ramen; Gen mentioned cola, making Senku recognize him as someone from the modern world.
• Kohaku, Kinro, and Ginro surrounded Gen, but Senku recognized Gen Asagiri and greeted Chen Yu, who noted that Senku’s injury had healed.
• Senku warned Kinro and Ginro that Chen Yu might be carrying poison, frightening Gen and Kohaku, then assured Kohaku that Chen Yu would never harm someone he was trying to save.

Chen Yu tested Senku’s thread and used it to diagnose his weakened lungs and muscles, then agreed to spar with Kohaku. He defeated her with Tai Chi, and Senku asked the group to explain why they had come to the village.

• Kohaku told Kinro and Ginro to watch Gen, while Kinro remained wary of Chen Yu.
• Chen Yu tested Senku’s thread, diagnosed strain on Senku’s lungs and muscles, and asked for stronger thread and specialized tools.
• Kohaku challenged Chen Yu to a match, and the villagers gathered to watch.
• Chen Yu blocked Kohaku’s charge with a fan and used Tai Chi to redirect her attacks until she collapsed and admitted defeat.
• Chen Yu helped Kohaku up and explained adrenaline, then Senku asked why the group had come to the village.

Gen saw hope in Senku’s ironmaking and Chen Yu’s medical knowledge, and decided he would report Senku’s death to Tsukasa. Chen Yu then frightened Gen by claiming he had poisoned him, leaving Gen unconscious after he swallowed the supposed antidote.

• Gen and the villagers upgraded the Ironworks by pumping its bellows, while Senku asked Gen whether Taiju and Yuzuriha were doing well.
• Gen said Senku’s science and Chen Yu’s legacy had given him hope, and explained that he had originally planned to report Senku’s death to Tsukasa.
• Chen Yu examined Kohaku’s herbs and explained how he had learned traditional medicine by tasting herbs.
• Gen said iron weapons could change the balance against Tsukasa, though he was still unsure which side to support.
• Chen Yu forced Gen to swallow a pill and claimed it was poison, then gave him another pill after Gen begged for an antidote.
• Chen Yu revealed that the first pill was a health supplement and the second was poison, and Gen fainted.

Chen Yu persuaded Gen to consider joining Senku’s side, then used a trick with his wooden fan to drive off Magma and his companions. The group returned to Chen Yu’s ginger soup, while Senku agreed to consider making the special needles Chen Yu wanted.

• Chen Yu explained why life with Senku offered Gen a better future, and Gen admitted Chen Yu understood his dilemma.
• Senku revealed that he planned to build a power plant, while a storm approached and Chrome found copper for their work.
• Chen Yu prepared ginger soup as Senku and the others worked on a magnet, then stepped forward when Magma and two men arrived.
• Chen Yu threatened Magma’s companion with a pebble propelled by his wooden fan and used his presence to make another man flee, so Magma’s group withdrew.
• Chen Yu asked Senku to make the short, thin needles he had used before, then took Suika to join Gen for ginger soup.

Chen Yu helped Senku and the villagers prepare a generator while explaining his silver needles and reassuring Gen that he had not poisoned him. As the generator began operating, Chen Yu built a sleeve arrow for self-defense, unaware that Magma was targeting him.

• Senku explained that Chen Yu's silver needles could temporarily stiffen muscles, and Chen Yu confirmed that the tonic he gave Gen was not poison.
• Senku obtained a magnet, the villagers shaped copper sheets, and Chen Yu checked that the exhausted workers were unharmed.
• Chen Yu gave Senku ointment for his reaction to paint, and Senku's group completed the makeshift generator by dusk.
• Senku's group asked Kinro and Ginro to operate the generator while Chen Yu stayed behind to build a miniature mechanism.
• Chen Yu made a sleeve arrow and thought he had spared Gen from a future ambush, but Magma was actually watching Chen Yu.

Chen Yu and Senku helped the Kingdom of Science create its first bamboo-filament electric light, while Senku explained the conflict with Tsukasa and the others debated where Gen and Chen Yu stood. Gen chose the Kingdom of Science as the more interesting side, then learned not to call Chen Yu “little Yu-Yu.”

• Chen Yu finished the wooden parts for the Sleeve Arrow and joined Senku as he prepared a bamboo-filament light bulb.
• Senku connected the wires, illuminating the settlement and giving the Globe its first electric light, though they still needed tungsten filament for durable bulbs.
• Kohaku told Chrome and Suika about Tsukasa, and Senku explained that Gen was neither good nor bad while Chen Yu opposed war.
• Chen Yu asked Gen what he thought after hearing the discussion, and Gen said the electric light made the Kingdom of Science more interesting than Tsukasa’s side.
• Gen teased Chen Yu by calling him “little Yu-Yu,” so Chen Yu hit him and warned him not to use the nickname.

Chen Yu captured Magma after he ambushed Gen and confronted the village chief, Kokuyo, demanding compensation and warning that the attack could mean war. Kohaku confirmed Magma had attacked him, leaving Kokuyo under pressure to make amends.

• Magma ambushed Gen, but Chen Yu intercepted him and immobilized him until morning.
• Chen Yu dragged Magma to the village entrance and demonstrated how Magma had struck at him.
• Chen Yu accused the village of effectively declaring war and demanded compensation, prompting Kokuyo to plead with him to name what he wanted.
• A villager questioned whether Magma had attacked Chen Yu, but Kohaku confirmed that she had witnessed the attack.
• Chen Yu asked Kokuyo how the village would compensate him, and Kokuyo felt the pressure mount.

Chen Yu took Magma and his shorty accomplice away after Kokuyo agreed to help Senku’s group, then punished them for harming others. The beating ended with Chen Yu telling Magma that he might be related to Senku by blood, leaving Magma stunned.

• Kokuyo agreed to help Senku’s group, and Chen Yu asked him to hand over Magma and the shorty while promising to keep them safe.
• Chen Yu took Magma and the shorty to a deserted spot and fought them, criticizing their misuse of strength and schemes.
• Chen Yu wore down the shorty first, then continued beating Magma as he lectured him about valuing his healthy body and not hurting others.
• Magma questioned why he had to listen to Chen Yu, who replied that Magma’s people might be related to Senku by blood.
• Magma was stunned by Chen Yu’s claim about their possible ancestry.

Chen Yu explained to Magma that the villagers were likely descendants of people who survived the petrification, prompting Magma and Shorty to change their behavior. Chen Yu and Gen returned home after finding Senku’s stone tablet, and Chen Yu reached his dispensary, where a stranger failed to recognize him.

• Chen Yu explained to Magma that the villagers might descend from the people who escaped the petrification, and urged him to consider their ancestors before harming others.
• Magma returned to the village with Shorty and became courteous and helpful, showing special care for the elderly and children.
• Chen Yu and Gen discussed what to tell the others, then found a stone tablet near the cave that revealed Senku had counted the years in the darkness.
• Gen realized Senku had kept track of time for 3,700 years and told Chen Yu which side he would support.
• Tsukasa’s people escorted Chen Yu and Gen back, separating them; Chen Yu went to his dispensary while Gen went to see Tsukasa.
• A stranger challenged Chen Yu at the dispensary, and Chen Yu told him it was his own place.