The Strongest Man
Saitama is a guy who's a hero for fun. After saving a child from certain death, he decided to become a hero and trained hard for three years.
The Lone Cyborg
A monster is moving toward City Z, one that has been created by the mysterious organization known as The House of Evolution.
The Obsessive Scientist
Saitama and Genos glean information about The House of Evolution and its founder Dr. Genus, who learns of Saitama's amazing strength and has plans of his own for One-Punch Man.
The Terrifying City
When Saitama learns that C-class heroes who don't fight bad guys are dropped from the hero registry after a week of inaction, he heads out to find any criminals or monsters to stop.
The Deep Sea King
Saitama and Genos head to the shores of City J to stop a pack of monsters calling themselves the "Clan of the Seafolk".
As the battle with the Deep Sea King reaches its climax, more heroes fall to the aquatic despot's brutal attacks.
Saitama tags along to an emergency meeting of Class S heroes and discovers that a seer has foretold a serious danger threatening the Earth.
The Dominator of the Universe
As a colossal spaceship floats in the skies above City A, a member of its monstrous crew battles on the ground against a group of S Class heroes.