Spoiler warningThis site contains descriptions of story developments.

One-Punch Man

A story of Saitama, a hero so powerful he defeats any enemy with one punch, who seeks true excitement while battling formidable foes. Based on ONE's webcomic, with the remake manga drawn by Yusuke Murata (serialized in Tonari no Young Jump) and three anime seasons. Set in fictional modern cities, centered on the conflict between the Hero Association and monsters.

Genre:
バトル / アクション / コメディ / SF / ヒーロー
Medium:
Manga / Anime
Add to cross timeline
Share:

One-Punch Man — Timeline19 events

Three Years Before Hero ActivitiesMajorEstimated

Saitama Begins Grueling Training to Become a Hero for Fun

After struggling with job hunting, Saitama encounters a monster by chance and decides to become a hero for fun. He undertakes an extreme self-imposed training regimen—100 push-ups, sit-ups, and squats plus a 10km run every day. After three years, his hair falls out completely and he attains an overwhelming power capable of defeating any opponent in a single punch.

Explicitly shown in Chapter 1 via Saitama's flashback. The three-year training regimen and hair loss are core setting details.

サイタマ特訓ヒーロー志望強さの起源世界観ヒーロー活動以前
Around the Start of Hero ActivitiesMajorEstimated

The Hero Association Founded by Wealthy Businessman Agoni

Wealthy businessman Agoni, after having his grandson saved from a monster, founds the privately run Hero Association. The organization classifies heroes into ranks from C to S class and establishes a systematic response to monster threats. By the time Saitama and Genos join, several years have passed since its founding.

Referenced across multiple chapters as world-building backstory. No exact founding year is given.

アゴーニヒーロー協会設立組織世界観ヒーロー協会時代
Just Before Joining the Hero AssociationMajorEstimated

Cyborg Genos Requests to Become Saitama's Disciple

The fully-modified cyborg Genos appears in City Z while pursuing the monster Mosquito Girl, only to encounter Saitama after being overwhelmed. Witnessing Saitama's overwhelming power firsthand, Genos immediately requests to become his disciple, and Saitama agrees on the condition that they both join the Hero Association.

Early chapters of the remake, Genos's first appearance episode. Key scene establishing the master-disciple relationship.

サイタマジェノスモスキート娘師弟関係弟子入りジェノス登場ヒーロー協会時代
Immediately After Joining the Hero AssociationMajorEstimated

Saitama and Genos Take the Hero Exam; Genos Ranks S-Class 17th

The two take the Hero Association exam. Genos dominates the physical and combat tests and is certified S-Class rank 17. Saitama also achieves record-breaking physical results but scores poorly on the written exam, placing him at the very bottom of C-Class (rank 388).

Exam results and ranks explicitly stated in-story. The low written score is given as the reason for Saitama's C-Class placement.

サイタマジェノスヒーロー試験ヒーロー協会加入ランク制度ヒーロー協会時代
Early Period After Joining the Hero AssociationMinorEstimated

Saitama Begins Activities in C-Class, Facing the Weekly Quota Rule

C-Class heroes must perform at least one heroic activity per week or be removed from the roster. To avoid removal, Saitama routinely defeats monsters in his daily life, gradually accumulating enough points to rise through the ranks.

The C-Class weekly activity requirement is an explicitly stated institutional rule in-story.

サイタマC級活動ランク制度日常ヒーロー協会時代
Deep Sea King Arc (Early Hero Association Period)MajorEstimated

Sea Folk Invade Land; Deep Sea King Defeats Multiple A- and S-Class Heroes

Sea Folk land and invade City J. A-Class hero Stinger fights valiantly but is instantly defeated by the Deep Sea King, as is S-Class hero Puri-Puri Prisoner. Transformed into his true form in the rain, the Deep Sea King breaks through an evacuation shelter, and Genos also suffers heavy damage. Saitama arrives and defeats the Deep Sea King in a single blow, saving the civilians.

Corresponds to Episodes 8-9 of Season 1 anime and the remake manga equivalent. The Deep Sea King's threat level and battle details are depicted in-story.

サイタマジェノス深海王スティンガープリプリプリズナー海の民深海王都市J一撃撃破ヒーロー協会時代
Meteor Strike and S-Class Summoning ArcMajorEstimated

S-Class Heroes Emergency Summoned on Prophet's Warning; Giant Meteor Targets City Z

Prophet Shibabawa dies leaving the message 'the Earth is in trouble,' prompting the Hero Association to summon all S-Class heroes in an emergency. Shortly afterward, a giant meteor enters a collision course with City Z, where Saitama lives. Genos attempts to stop it at the cost of his own body but fails, and Saitama destroys it in a single punch to protect the city.

Corresponds to Episodes 6-7 of Season 1 anime and the remake manga equivalent. The S-Class summoning is triggered by Shibabawa's prophecy.

サイタマジェノスシババワシルバーファング隕石落下S級招集都市Z一撃撃破予言ヒーロー協会時代
Dark Matter Thieves Invasion ArcMajorEstimated

Alien Group Dark Matter Thieves Bombards City A and Invades Earth

The 'Dark Matter Thieves,' led by Boros—a cosmic pirate who has ravaged the entire universe—arrive above City A in a massive spaceship and destroy the city with cannon fire. S-Class heroes battle the invading forces on the ground while Saitama infiltrates the ship alone, defeating the top executives before confronting Boros.

Corresponds to the final episodes of Season 1 anime and the remake manga equivalent. Boros is established in-story as one of the strongest beings in the universe.

サイタマボロスジェノスタツマキ宇宙人侵攻暗黒盗賊団ダークマター都市A宇宙船S級対決ヒーロー協会時代
Dark Matter Thieves Arc: ConclusionMajorEstimated

Saitama Defeats Boros in One Punch—A Clash Against His First Truly Worthy Opponent

Boros, who traveled 20 years to reach Earth seeking the prophesied warrior capable of fighting him, unleashes his full power in a one-on-one duel with Saitama. It is the first time Saitama has faced an opponent whose attacks registered against him, but he ultimately defeats Boros in a single blow with his final technique 'Meteoric Burst.' Surviving Dark Matter soldiers are subsequently executed by Handsome Kamen.

Depicted in detail in the remake manga. A pivotal showdown establishing Boros as the only being to have exchanged blows with Saitama on nearly equal footing.

サイタマボロスアマイマスクボロス撃破最強決戦一撃宇宙人ヒーロー協会時代
Hero Hunt Arc Begins (Garou Arc, First Half)MajorEstimated

Former S-Class Disciple Garou Begins His 'Hero Hunt'

Garou, a former disciple of Silver Fang who was expelled, despises heroes as hypocrites based on his childhood experiences and sets out to become a 'human monster,' launching his personal hero hunt. He defeats A- and B-Class heroes one after another, spreading his name throughout the Hero Association.

Corresponds to Season 2 anime and the remake manga equivalent. Garou's motivations and ideals are explicitly articulated in-story.

ガロウシルバーファング(バング)ヒーロー狩りガロウ登場人間怪人反ヒーローヒーロー協会時代ガロウ編
Super Fight Arc (Mid-Garou Arc)MajorEstimated

Martial Arts Tournament 'Super Fight' Held; Saitama Participates in Disguise

The martial arts tournament 'Super Fight' is held, and Saitama participates in disguise as Charanko. Four-time champion Suiryu demonstrates overwhelming technique, but in the finals Saitama's casual movements send him flying out of the ring. Garou also appears at the venue, and the first Super Fight champion Gouketsu invades after having monsterized.

Original episode in the remake manga. Suiryu and Gouketsu were later back-imported into the original webcomic from the remake.

サイタマガロウスイリューゴウケツスーパーファイト武術大会怪人化変装ヒーロー協会時代ガロウ編
Monster Association Arc BeginsMajorEstimated

Monster King Orochi's 'Monster Association' Declares War on the Hero Association

The large-scale Monster Association led by Monster King Orochi (an original character in the remake) takes the Hero Association chairman's grandson hostage and declares war. The organization, headquartered in an underground fortress in the former ghost town of City Z, houses over 500 monsters, many of whom are classified at Threat Level Demon or higher.

Corresponds to Seasons 2-3 anime and the remake manga. Orochi is an original Monster Association leader character exclusive to the remake.

オロチサイコスガロウ怪人協会宣戦布告人質地下要塞都市Zヒーロー協会時代怪人協会編
Monster Association Arc: MidpointMajorEstimated

Hero Association Launches Full Assault on Monster Association's Underground Fortress with All S-Class Heroes

The Hero Association assembles a unit centered on S-Class heroes and launches a full-scale assault on the Monster Association's underground fortress. Tatsumaki deploys her psychic powers to physically drag the fortress to the surface in a massive operation, while underground Garou rapidly evolves through consecutive battles against Silver Fang and multiple S-Class heroes.

Depicted in detail in the remake manga. Episodes center on Tatsumaki's massive psychic feat and the efforts of each S-Class hero.

タツマキシルバーファング(バング)ガロウジェノス怪人協会S級総攻撃地下要塞タツマキガロウ進化ヒーロー協会時代怪人協会編
Monster Association Arc: Late StageMajorEstimated

Saitama Defeats Orochi; Gyoro Gyoro's True Identity as Psykos Revealed

Saitama infiltrates the Monster Association's underground headquarters alone and defeats Monster King Orochi in a single blow. It is also revealed that Gyoro Gyoro, who has been manipulating the Monster Association from behind the scenes, is actually the esper Psykos, who is subdued by Tatsumaki after a fierce battle.

Depicted in the remake manga. Orochi is exclusive to the remake; the Gyoro Gyoro = Psykos revelation is a major plot twist.

サイタマオロチサイコスタツマキオロチ撃破サイコス正体一撃怪人協会壊滅ヒーロー協会時代怪人協会編
Garou Arc: Pre-ClimaxMajorEstimated

Garou's Monsterization Progresses; He Surpasses Multiple S-Class Heroes

Through combat with the Monster Association, Garou's body undergoes rapid monsterization. Having assimilated Silver Fang's Flowing Water Rock Smashing Fist into his fighting style, Garou's evolving power exceeds the speed of Platinum Sperm and shatters the Centipede Elder's reinforced exoskeleton, surpassing multiple S-Class heroes in combat ability. Hints emerge that a mysterious entity known as 'God' is influencing his abnormal evolution.

Depicted in detail in the remake manga. Centers on Garou's continuous evolution through consecutive battles against formidable opponents.

ガロウシルバーファング(バング)タツマキジェノスガロウ進化怪人化S級超越神の存在ヒーロー協会時代ガロウ編
Garou Arc: ClimaxMajorEstimated

Garou Receives Power from 'God' and Awakens to Cosmic Fear Mode

The mysterious supreme entity 'God' contacts Garou and grants him its power. Awakened to Cosmic Fear Mode, Garou's body bears galaxy-like patterns and he constantly emits cosmic radiation, displaying combat power that overwhelms all S-Class heroes. Genos suffers severe damage when his core is stolen during the battle.

Depicted in the remake manga. The scene where 'God' grants power to Garou is a pivotal turning point in the narrative.

ガロウジェノスガロウ覚醒コズミックフィアーモード神の力宇宙的恐怖ヒーロー協会時代ガロウ編
Garou Arc: ResolutionMajorEstimated

Saitama vs. Garou: Final Battle in Space and Saitama's Time Reversal

With Genos destroyed, Saitama fights seriously and clashes with God-powered Garou in outer space. Saitama copies Garou's 'God Fist' technique and then surpasses even that, ultimately reversing time to prevent Genos's death. After his defeat, Garou reflects on his actions through a reunion with Tareo and begins a path of rehabilitation under Silver Fang.

Depicted in detail in the remake manga. Time reversal is depicted as a newly revealed facet of Saitama's abilities. Silver Fang subsequently retires as a hero to become Garou's guardian.

サイタマガロウジェノスシルバーファング(バング)タレオサイタマ対ガロウ宇宙空間決戦時間逆行ガロウ更生ガロウ編決着ヒーロー協会時代ガロウ編
Post-Garou Arc: Latest DevelopmentsMajorInterpretation

The Mysterious Entity 'God' and Its Threat to Humanity Increasingly Implied

The entity 'God,' which intervened through Garou, is implied to be a being that grants power to monsters and humans alike, intending humanity's annihilation. Connections to the moon as its base and to S-Class Rank 1 hero Blast are also hinted at. Following the Garou Arc, 'God' increasingly emerges as the overarching final antagonist of the story, with the Hero Association and various heroes beginning to prepare for this new threat.

Based on depictions in the remake manga. The true identity and purpose of 'God' have not been fully revealed in-story and remain at the level of implication.

ブラスト神の存在人類の脅威黒幕最終局面の予兆ヒーロー協会時代神編
Recurring Theme Throughout the StoryMinorEstimated

Saitama's Rank Progression: From C-Class 388th to A-Class 39th

Starting at the very bottom of C-Class (rank 388) when joining the Hero Association, Saitama gradually rises—C-5, C-2, B-63, B-7, A-39—as his monster-defeating activities become recognized through citizen reports. The gap between his true ability and his official standing is a recurring undercurrent of the story.

Each rank is explicitly stated in-story. The progression spans from the early story to the current period as a longitudinal setting detail.

サイタマランクアップ評価ヒーロー協会能力と評価のギャップヒーロー協会時代

About data reliability: This is an unofficial, fan-made site. All rights to each work belong to their respective owners. It is an index and guide to the official works, not a substitute for them.