This page is meant to catalogue all major events in the One-Punch Man universe in chronological order.
|Before the series|
|Date||Fights, Battles & Events||Image|
21 Years Prior
|Tatsumaki is sent off to be tested because of her extraordinary powers.|
20 Years Prior
|Boros and the Dark Matter Thieves begin their journey to planet Earth after receiving a prophecy stating that they will find a worthy opponent for Boros there.|
18 Years Prior
|Tatsumaki is saved by Blast.|
13 Years Prior
| Saitama enters Middle School and is beaten by Piggy Bancon.|
Mumen Rider attends the same school and is beaten by some delinquents.
12 Years Prior
|15 years old Superalloy Darkshine begins his daily lifting training after receiving weights for his birthday.|
11 Years Prior
|Gouketsu wins the first Super Fight tournament.|
11 Years Prior
|Gouketsu fights Orochi and loses, then eat the monster cell.|
10 Years Prior
|Zombieman escapes from the House of Evolution.|
4 Years Prior
|Genos' town and family are destroyed by a mad cyborg.|
Dr. Kuseno saves Genos, and transforms him into a cyborg.
3 Years Prior
|Saitama saves a young child from Crablante which he began his childhood goal of becoming a hero, and begins his training.|
Sometime after the event, Agoni founded the Hero Association.
2.5 Years Prior
|S-Class is created.|
|Saitama's 300th day of training||Saitama defeats Himaaku, and later Personification Of A Light Pull Cord.|
|More than 1.5 years prior||Saitama defeats Octopus Claw Man and saves King.|
|More than 1.5 years prior|| Saitama's hair begins to fall out.|
170,000-Year Magicicada Nymph attacks Z-City, but is killed by Saitama.
|More than 1 year prior||Metal Bat is promoted to S-Class, and receives his signature metal bat.|
|Less than One Year Prior||Garou beats up and incapacitates his fellow disciples and is promptly expelled from Bang's dojo.|
|Six Months Prior||Garou steals the identity of Wolfman, and uses his identity to win the Super Fight Tournament.|
His victory earns him the attention of Suiryu, a famous martial artist and previous 4-time winner of Super Fight.
|Less than One month Prior||Homeless Emperor obtains his powers from God.|
|Date||Fights, Battles & Events||Image|
|Present||Saitama has now become a powerful hero for fun, capable of killing monsters in one punch. Saitama saves cities from Vaccine Man, Marugori, Super Custom YO649Z Mk. II and the Subterranean King.|
|Next Day|| Saitama meets Genos, saving him from Mosquito Girl.|
Dr. Genus orders his minions to bring Saitama to the House of Evolution.
|1 Week Later|| Genos begins his tutelage under Saitama's guide. Soon after, Saitama's apartment is attacked.|
The duo infiltrate the House of Evolution's headquarters and combat Carnage Kabuto and destroy him. Dr. Genus' life is positively changed after Saitama's actions.
|1 Day Later|| Hammerhead and the Paradise Group begin their attack, but are defeated by Speed-o'-Sound Sonic and Saitama.|
Saitama meets Sonic and defeats him.
|1 to 2 Days Later|| Saitama and Genos attend the Hero Association exam and pass. Genos becomes an S-Class hero, while Saitama becomes a C-Class hero.|
Sneck attempts to fight Saitama but is defeated.
Genos and Saitama spar and Saitama is overwhelmingly victorious.
|7 Days Later||Saitama encounters Speed-o'-Sound Sonic during his search for a criminal in order to accomplish his weekly hero quota. Saitama quickly dispatches him and is promoted to C-Class rank 342.|
Golden Ball and Spring Mustache are sent to investigate Z-City's ghost town, where they encounter Kombu Infinity who defeats them.
|Unknown||A giant meteor heads towards Z-City. S-Class hero Metal Knight and Genos fail to stop it, but Saitama manages to shatter the meteor, though he is unable to prevent collateral damage to the city.|
|3 Days Later||Tanktop Tiger and Tanktop Black Hole accuse Saitama of taking credit for the S-Class heroes' role in destroying the meteor, and challenge him to a battle.|
|Several days after||Deep Sea King and his Seafolk begin their invasion of the surface world, starting with J-City, many heroes failed to defeat the Deep Sea King|
Sonic and S-Class hero Puri-Puri-Prisoner escape prison, and encounter the Deep Sea King.
|Hours Later||The Deep Sea King finds the shelter and later fights Genos and defeats him.|
Mumen Rider arrives to stop the Sea King, and gives a speech acknowledging his lack of power.
Saitama defeats the Sea King with ease and pretended to be a cheat in order to rally support for the defeat heroes, which worsened his reputation.
|1 Day Later||Saitama is promoted to Rank 1 in C-Class and then decides to move up to B-Class. He now has to start from the bottom of B-Class Rank 101.|
|Unknown||Shibabawa foresees a great tragedy that will result in the Earth's destruction. She develops a couching fit and dies choking on a cough drop she swallowed.|
Saitama is promoted to B-Class Rank 63.
|Unknown||All S-Class heroes are called to the Hero Association for an emergency meeting. All the S-Class heroes except Blast and Metal Knight show up to the meeting where it is revealed by Sitch that the earth is in great danger.|
|Boros and the Dark Matter Thieves arrive to A-City and destroying it.|
Iaian loses his left arm against Melzalgald.
Melzalgald is killed by the combined efforts of Metal Bat, Puri-Puri-Prisoner, Atomic Samurai, and Bang.
|Saitama confronts the leader of the Dark Matter Thieves, Lord Boros and they began to fight.|
Boros uses "Collapsing Star Roaring Cannon" to destroy the planet, but Saitama counters the attack killing Boros.
|1 Day Later||Tanktop Master trains to prove his strength can compete with Tatsumaki's psychic powers. After being humiliated by Metal Knight, Tanktop Master trains to surpass Metal Knight's machinery as well as Tatsumaki's psychic powers.|
|1 Week Later||Metal Knight rebuilds A-City and turns it into an unbreakable fortress.|
The monster Pluton attacks Y-City and Z-City, but is destroyed by Saitama.
|Unknown||G4 attacks King, but King runs away and Genos fights in his place. King is revealed to be a fraud and inadvertently took credit for defeating 5 monster Saitama defeated.|
|Unknown||Sitch holds a meeting in an attempt to recruit criminals to help deal with the monster uprisings. Garou attends this meeting, defeats three heroes and all of the criminals there declares his hero hunt.|
Fubuki tries to convince Saitama into joining the Blizzard Group, but fails.
Speed-o'-Sound Sonic fights Genos to a draw.
Garou defeats Mumen Rider, the Tank Topper Army, Charanko, Golden Ball and Spring Mustache on his hero hunt.
|Unknown||Saitama decides to join the Super Fight Tournament under Charanko's name.|
Garou attacks Saitama, who he believes to be a hero searching for him and is defeated.
|1 Day Later||Metal Bat is assigned to protect Narinki and his son Waganma from Garou. He confronts 4 Demon level threats and defeats them.|
|Hours Later||Elder Centipede attacks S-City and Metal Bat attempts to stop him, but ends up fighting Garou. Meanwhile the Monster Association begin their invasion.|
Metal Knight arrives in attempt to defeat Elder Centipede but fails. The monsters kidnap Waganma.
|Hours Later||The Super Fight tournament begins, with Saitama being in the semi-finals along with Volten, Choze and Suiryu. Genos eliminated all the monster in C-City, but was defeated by Gouketsu.|
|Hours Later||Do-S encounters Fubuki and the Blizzard Group|
Do-s' uses Fubuki to bring Tatsumaki.
|Hours Later||Child Emperor and Pig God fight Eyesight.|
Drive Knight goes around killing monsters and interrogates one for info about the monster invasion.
Garou fights Watchdog Man.
|Hours Later||Flashy Flash fights Hundred-Eyes Octopus, but Tatsumaki intervened.|
Atomic Samurai and his students decide to strike the Monster Association
Saitama came into the finals of the Super Fight, where his disguise was blown and is disqualified.
Gouketsu traps all the Martial Artist and holds the Super Fight Stadium hostage.
- In the Original Webcomic, Saitama became a professional hero 65 days ago. In 43 days became a B-Class hero and is currently 2 days in A-Class