Chapter Summaries

Zenin Tachibana found himself in a world where humans and monsters coexisted and discovered that he could cultivate Haki, Chakra, and soul power despite losing his Cursed Energy. After rapidly growing stronger, he returned to the city and intervened when a monster shaped like a phone booth attacked a young man.

• Zenin Tachibana, confused in Z-City, checked his body and found that his Cursed Energy was gone.
• Zenin Tachibana awakened Observation Haki and found he could also synthesize Chakra and use soul power, allowing him to work toward creating Star Power.
• Zenin Tachibana trained in the wasteland for half a day, rapidly strengthening his body, Chakra, Haki, and Reiatsu.
• Zenin Tachibana noticed that absorbing vast amounts of energy did not diminish the energy surrounding him and returned to the city with his system set to cultivate idly.
• Zenin Tachibana found a phone booth monster beating up a blond young man with a smartphone and asked them to stop fighting.

After arriving in the One Punch Man world, Zenin Tachibana settled in Z-City, trained alongside Saitama for three years, and grew powerful while Saitama became bald and virtually invincible. Zenin Tachibana later showed Saitama his B-Class Hero card, leaving Saitama confused about the Hero Association and the rewards he had missed.

• Zenin Tachibana obtained a resident ID and money in Z-City, then watched Saitama defeat Crablante and moved in next door.
• Zenin Tachibana copied Saitama’s training routine for three years, reached planet-busting strength, and concluded that Saitama remained stronger.
• Zenin Tachibana ended their austere lifestyle, bought generators, and regularly cooked meals for Saitama, who visited with discounted groceries.
• Saitama spent hours playing Cockroach Warrior and learned he had crushed five of Zenin Tachibana’s controllers, which supposedly cost 600,000 yen.
• Zenin Tachibana showed Saitama his Rank 6 B-Class Hero card and asked whether Saitama knew how much he could have earned from the Hero Association for defeating monsters.

Zenin Tachibana took Saitama to the Hero Association, where Saitama earned the lowest C-Class rank despite breaking every physical test record. Meanwhile, Hell's Blizzard learned that Zenin Tachibana had rejected the Blizzard Group's invitation and set out to confront him in Z-City.

• Saitama decided to register as a hero, and Zenin Tachibana named him One-Punch Man.
• Zenin Tachibana brought Saitama to the Hero Association, where Saitama broke every physical test record but placed last in C-Class because of his written exam.
• Eyelashes told Hell's Blizzard that Zenin Tachibana had rejected the Blizzard Group's invitation despite his potential.
• Hell's Blizzard learned that the Association had Zenin Tachibana's Z-City address and ordered a helicopter so she could go there.

Zenin Tachibana celebrated Saitama becoming a professional hero, then refused Hellish Blizzard’s demand to join the Blizzard Group. Blizzard challenged him to a fight, with his membership on the line.

• Zenin Tachibana and Saitama fought over the last slice of beef, and the clash further boosted Saitama’s strength.
• Zenin Tachibana beat Saitama hundreds of times in King of Fighters '97.
• Hellish Blizzard arrived by helicopter with her underlings and asked Zenin Tachibana to join the Blizzard Group.
• Zenin Tachibana refused, calling the Blizzard Group low-class, and Blizzard challenged him to fight: if he lost, he would join her group.

Zenin Tachibana defeated Hell Fubuki with one punch after blocking her psychic attack, then left with Saitama to visit a supermarket. After seeing a photo of her humiliated sister, Tatsumaki flew toward Z-City to confront him.

• Zenin Tachibana and Saitama jumped from the eleventh floor and waited on the ground as the Blizzard Group watched in shock.
• Hell Fubuki attacked them with a powerful gale, but Zenin Tachibana blocked it with Star Power.
• Zenin Tachibana struck Hell Fubuki once, making her vomit, then left with Saitama for a supermarket promotion.
• A Blizzard Group member photographed Hell Fubuki and sent the image to Tatsumaki.
• Tatsumaki saw the photo, shook the Hero Association building with her psychic power, and flew toward Z-City to face Zenin Tachibana.

After Hell Blizzard recovered from Zenin Tachibana’s overwhelming punch, Tatsumaki flew to Z-City to confront him and began demolishing buildings in the Uninhabited District. Saitama intervened, but Tatsumaki mistook his connection to Tachibana as a reason to attack him, while Tachibana remained at home watching TV.

• Hell Blizzard concluded that Zenin Tachibana was powerful enough to defeat her in an instant and left with her subordinates.
• Tatsumaki called Blizzard, learned she had been beaten, and flew to Z-City while promising to punish the person responsible.
• Blizzard realized her sister was heading toward Tachibana and chased after her to prevent a fight.
• Tatsumaki destroyed nearby buildings in the Uninhabited District to draw out the man who had beaten Blizzard.
• Saitama confronted Tatsumaki over the destruction, but she flung him away with her psychic powers.
• Blizzard tried to stop Tatsumaki, but when Saitama mentioned knowing Tachibana, Tatsumaki attacked him with giant stone spheres.

Saitama punched Tatsumaki hard enough to make her vomit, and Zenin Tachibana destroyed the falling stone spheres before they could devastate Z-City’s abandoned district. After Tatsumaki and Fubuki argued and flew off in opposite directions, Zenin Tachibana and Saitama headed home, with Tachibana offering to teach Saitama to fly.

• Tatsumaki froze the stone spheres and pulled Saitama toward her, then struck his forehead with telekinetic force without harming him.
• Saitama punched Tatsumaki in the abdomen, making her vomit and lose control of the stone spheres as they began falling toward Z-City’s abandoned district.
• Hell Fubuki tried to hold Saitama and Tatsumaki aloft, but Zenin Tachibana appeared and dissolved every falling stone sphere with a sword of Star Power.
• Tatsumaki recognized Zenin Tachibana’s strength, while Fubuki and Tatsumaki argued before flying away in opposite directions.
• Saitama fell headfirst into the ground and emerged unharmed, then followed Zenin Tachibana home as Tachibana asked whether he wanted to learn to fly.

Zenin Tachibana taught Saitama the Sky Walk technique, and Saitama quickly learned to fly and began patrolling three cities, rapidly rising through the Hero Association rankings. As Saitama headed to G-City, Tachibana saw an emergency report about a massive mosquito infestation in Z-City and anticipated Genos's arrival.

• Zenin Tachibana refused Saitama's request to fight and promised to teach him how to fly the next day.
• Zenin Tachibana demonstrated his Sky Walk technique on the outskirts of Z-City, and Saitama learned it within minutes.
• Saitama began flying over Z-City, G-City, and F-City to find monsters, keeping busy as he defeated them with single blows.
• Saitama's hero ranking rose from last in C-Class to thirty-eighth in A-Class, and the Hero Association designated his hero name as One-Punch Man.
• Zenin Tachibana dealt with powerful monsters in abandoned districts while Saitama received public recognition and rose in rank.
• Zenin Tachibana watched an emergency bulletin about a massive mosquito infestation in Z-City and anticipated Genos's appearance.

Zenin Tachibana saved Genos from Mosquito Girl, accepted him as his disciple, and brought him into conflict with the House of Evolution. After Genos joined him in defeating the organization's capture squad, they reached its headquarters and began their attack.

• Zenin Tachibana killed Mosquito Girl before she could strike Genos, then accepted the rescued cyborg as his disciple after hearing about his quest to kill the evil cyborg who destroyed his hometown.
• Genos recovered with Dr. Kuseno’s help and visited Zenin Tachibana, where he met Saitama and learned that Saitama was as powerful as his new master.
• The House of Evolution sent a capture squad to seize Zenin Tachibana, who killed several monsters while Genos defeated Armored Gorilla; together, they forced the gorilla to lead them to the organization’s headquarters.
• Dr. Genus ordered his clones to prepare traps and consider releasing Carnage Kabuto as Zenin Tachibana and Genos approached the facility.
• Zenin Tachibana ordered Genos to blast the House of Evolution building flat, then tore open the steel plate at its true entrance.

Zenin Tachibana defeated Carnage Kabuto instantly and used genjutsu to make Dr. Genus obey him. He ordered the House of Evolution to relocate and focus its research on strengthening Genos, then explained to Genos that he intended to put the organization’s scientific capabilities to good use without allowing further human experiments.

• Dr. Genus offered Carnage Kabuto a week of freedom in exchange for help, while Zenin Tachibana demanded that a clone lead him to the House of Evolution’s ultimate weapon.
• Carnage Kabuto charged Zenin Tachibana, but Zenin Tachibana appeared in front of it and killed it with a single palm strike.
• Dr. Genus approached Zenin Tachibana and asked for a body sample, but Zenin Tachibana altered his memories with genjutsu and made him call him Boss.
• Zenin Tachibana ordered Dr. Genus to relocate the base, preserve the research materials, and develop a way to strengthen Genos without making him monstrous.
• On the way home, Zenin Tachibana told Genos he had changed Dr. Genus’s memories and planned to redirect the House of Evolution’s research toward helping people.

After training Genos in combat techniques, Zenin Tachibana took him to the Hero Association, where Genos became an S-Class hero and Tachibana's ranking rose to fifth in B-Class. Tatsumaki challenged Tachibana again, but he overpowered her and left with Genos.

• Genos returned to Zenin Tachibana for a spar, and Tachibana showed him how martial arts technique could overcome raw strength and speed.
• After training all afternoon, Tachibana invited Genos to rest and meet him the next day for the Hero Association examination.
• Genos was appointed the seventeenth S-Class hero after the Association mistakenly credited him with destroying the House of Evolution, while Tachibana rose to fifth in B-Class.
• Tachibana noticed Saitama had reached second in A-Class and worried that he might kill Sweet Mask, whose secret identity was a monster protecting humanity.
• Tatsumaki arrived at the Hero Association and attacked Tachibana and Genos; Tachibana's punch overcame her psychic defense, and he flew away with Genos.

After Zenin Tachibana defeated Tatsumaki, the Hero Association identified him as a powerful but low-ranked hero and concealed the incident. That night, he warned Saitama about Sweet Mask’s monster identity and possible assessment, before Saitama offered kelp from a Seaweed Monster for dinner.

• Hero Association staff reviewed footage of Zenin Tachibana defeating Tatsumaki and sent a medical team to treat her.
• The Association identified Zenin Tachibana as Light of Z-City, a B-Class Rank 5 hero, and decided to conceal his victory while improving its attitude toward him.
• At dinner, Zenin Tachibana told Saitama that Sweet Mask was a monster who had continued helping humanity and warned that he might assess Saitama, now A-Class Rank 2.
• After dinner, Saitama brought Zenin Tachibana a basket of kelp he had taken from a Seaweed Monster and suggested they eat it the next day.
• Genos offered to arrange artificial hair for Saitama through Dr. Kuseno, but Saitama declined, and Zenin Tachibana refused to eat the kelp for fear of going bald.

Zenin Tachibana flew into space and dissolved the meteorite that threatened to destroy Z-City. The Hero Association watched in amazement as Saitama arrived at Tachibana’s home for breakfast, unaware of what had just happened.

• Zenin Tachibana sensed a meteorite descending toward Earth and flew into space to stop it without calling Saitama.
• The Hero Association identified Z-City as the impact point and began evacuating its residents while sending information to nearby S-Class heroes.
• A staff member spotted Zenin Tachibana flying toward the meteorite and showed the footage to the Association executives.
• Zenin Tachibana stopped the meteorite with a Star Power-enveloped fist and dissolved it, preventing debris from reaching Earth.
• Saitama arrived at Zenin Tachibana’s home, and Tachibana served him kelp and pork rib soup.

After Saitama defeated the Deep Sea King, Sweet Mask brought him to J-City to assess him for S-Class. Sweet Mask transformed into a monster when Saitama identified him, and Saitama punched at his head as Sweet Mask demanded he leave.

• Saitama arrived in J-City and defeated the Deep Sea King with one punch, saving the heroes and civilians.
• Sweet Mask watched footage of Saitama's victory and went to J-City to test him for S-Class promotion.
• Zenin Tachibana sensed monsters gathering beneath Z-City but decided to wait until the Monster Association had assembled them all.
• Sweet Mask pulled Saitama away from his fans and drove him to the J-City coastline for the assessment.
• Sweet Mask punched Saitama, who emerged unharmed and called him a monster.
• Sweet Mask began transforming and attacked Saitama, but stopped his claws just above Saitama's head before Saitama punched toward him.

Saitama spared Sweet Mask after recognizing that his heart remained human, then demonstrated overwhelming power with a punch that carved a vast crater into the sea. The next day, Tatsumaki and Fubuki visited Zenin Tachibana’s home, where Tatsumaki demanded another fight and Fubuki insisted they had come peacefully.

• Saitama spared Sweet Mask, telling him to keep acting as a hero, and Sweet Mask saw the enormous fist-shaped crater Saitama had made in the sea.
• Sweet Mask arrived at Zenin Tachibana’s home with Saitama the next morning, where Saitama and Zenin Tachibana bickered over baldness and training.
• Sweet Mask introduced himself to Genos and praised Saitama, while Genos said Zenin Tachibana believed Saitama was his equal.
• Tatsumaki and Fubuki arrived, and Tatsumaki challenged Zenin Tachibana and Saitama to fight her again.
• Zenin Tachibana declined to fight and invited the sisters to eat and make peace, while Fubuki restrained Tatsumaki and insisted they had not come to fight.

After settling the conflict between the Tatsumaki sisters, Zenin Tachibana sensed Boros’s spaceship approaching Earth and tricked Saitama into leaving. He told Tatsumaki, Sweet Mask, and Genos about the alien threat and prepared to take them into outer space to confront it.

• Fubuki joined Zenin Tachibana and Saitama, and Tatsumaki stopped arguing after Zenin Tachibana reminded her that she had started their fights.
• Zenin Tachibana served Fubuki tonkotsu ramen and Tatsumaki rice in soup, while Sweet Mask realized how powerful Zenin Tachibana seemed.
• Zenin Tachibana sensed Boros’s spaceship approaching Earth and decided to face the aliens without Saitama, hoping to give the others a chance to fight.
• Zenin Tachibana lured Saitama away with a story about a half-price supermarket and asked Sweet Mask to stay behind.
• Zenin Tachibana explained that the aliens included several Dragon-level fighters and that Boros might approach god level, then invited Tatsumaki, Sweet Mask, and Genos to join him.
• Tatsumaki and Sweet Mask agreed to go with Zenin Tachibana, who said he could help them survive in outer space and wanted to keep the fight away from Earth.

Zenin Tachibana and three heroes entered the alien ship, where he confronted Boros while the others headed toward the energy chamber. After Tachibana split Boros and his palace with one strike, Boros regenerated and unleashed his Energy Release form.

• Zenin Tachibana protected Genos, Tatsumaki, and Sweet Mask with Star Power and flew them to the alien ship, leaving Fubuki behind.
• Tachibana told the three heroes to stay together and face the ship’s three Dragon-level fighters while he confronted Boros; Tatsumaki flew ahead with Genos and Sweet Mask following.
• Geryuganshoop learned that four enemies had boarded the ship and sent Groribas and Melzargard after the three approaching the energy chamber.
• Tachibana entered Boros’s palace, introduced himself, and told Boros that the prophesied opponent was Saitama, though he would fight Boros himself.
• Tachibana split Boros, his throne, and the palace with Mountain-Cleaving Strike, but Boros regenerated and activated Energy Release.

Zenin Tachibana overwhelmed Boros in space until Boros sacrificed his life to unleash the Collapsing Star Roaring Cannon. Inside the spacecraft, Tatsumaki killed Groribas and fought Melzargard as Geryuganshoop headed to help; Zenin Tachibana’s clash with Boros’s final attack left Earth protected.

• Zenin Tachibana struck Boros through the spacecraft hull and followed him into space to keep their battle away from the ship.
• Tatsumaki stopped Groribas’s corrosive acid with her psychic power and hurled it back, killing him and forcing Melzargard to split into five bodies and attack.
• Melzargard secretly called Geryuganshoop for help, and Geryuganshoop flew from the control room toward the battle.
• Boros entered a life-burning state and repeatedly attacked Zenin Tachibana from a distance after being badly beaten in close combat.
• Boros unleashed the Collapsing Star Roaring Cannon at Zenin Tachibana and Earth, and Zenin Tachibana swung his cleaver to sever the beam while protecting the planet.

Zenin Tachibana defeated Boros, while Tatsumaki battled the alien elites aboard the spaceship. After Geryuganshoop nearly killed her, Tatsumaki awakened overwhelming psychic power and killed him and Melzargard, but Zenin Tachibana stopped her from tearing apart his captured ship and healed her.

• Boros was left shattered and dying after Zenin Tachibana neutralized the Collapsing Star Roaring Cannon, and Zenin Tachibana returned to the spaceship.
• Tatsumaki clashed with Geryuganshoop while Genos and Sweet Mask held off Melzargard, with Sweet Mask revealing his monster form.
• Geryuganshoop pierced Tatsumaki with alloy fragments, but the near-fatal attack awakened her immense psychic power.
• Tatsumaki killed Geryuganshoop and crushed Melzargard and his energy cores, then tried to rip apart the spaceship.
• Zenin Tachibana dispersed Tatsumaki's psychic power, told her the battle was over, and used Star Power to heal her injuries.

Zenin Tachibana defeated Boros and took control of his spaceship, then returned to Earth with Tatsumaki, Genos, and Sweet Mask. He planned to bring Dr. Genus and Dr. Kuseno to study the alien technology, while Saitama remained convinced that the half-price supermarket was real and would open again tomorrow.

• Tatsumaki discovered that her wounds had healed, and Zenin Tachibana explained Sweet Mask's transformation and his actions to her.
• Zenin Tachibana subdued the aliens, had Boros's body brought aboard, and left the spaceship in their custody before returning to Z-City with Genos, Sweet Mask, and Tatsumaki.
• Fubuki worried over Tatsumaki's damaged clothes, but Tatsumaki insisted she was unharmed.
• Zenin Tachibana told Genos that Dr. Kuseno could study the spaceship and arranged to bring Dr. Genus and the House of Evolution to Earth to examine its technology and Boros's body.
• Saitama returned home disappointed that he had not found the half-price supermarket, and Zenin Tachibana assured him the sale would last another week.