In the wake of defeating Boros and his mighty army, Saitama has returned to his unremarkable everyday life in Z-City. However, unbeknownst to him, the number of monsters appearing is still continuously on the rise, putting a strain on the Hero Association's resources. Their top executives decide on the bold move of recruiting hoodlums in order to help in their battle. But during the first meeting with these potential newcomers, a mysterious man calling himself Garou makes his appearance. Claiming to be a monster, he starts mercilessly attacking the crowd. The mysterious Garou continues his rampage against the Hero Association, crushing every hero he encounters. He turns out to be the legendary martial artist Silverfang's best former disciple and seems driven by unknown motives. Regardless, this beast of a man seems unstoppable. Intrigued by this puzzling new foe and with an insatiable thirst for money, Saitama decides to seize the opportunity and joins the interesting martial arts competition. As the tournament commences and Garou continues his rampage, a new great menace reveals itself, threatening the entire human world. Could this finally be the earth-shattering catastrophe predicted by the great seer Madame Shibabawa?

Specials included in the Blu-ray and DVD releases of One Punch Man.

Toua Tokuchi is a prodigy when it comes to both baseball and gambling. Pitching nothing but mediocre fastballs, he has made a name for himself by attaining 499 consecutive victories in the game of One Outs: a one-on-one showdown between a pitcher and a batter. Despite his remarkable abilities, however, Tokuchi sees the sport as nothing more than a way to make some quick money. When Hiromichi Kojima, a legendary hitter for the struggling Saikyou Saitama Lycaons, witnesses Tokuchi's skills firsthand, he realizes that the man might be exactly what the team needs to get out of their slump. Determined to recruit Tokuchi no matter what, Kojima places his own career on the line and defeats Tokuchi at his own specialty—One Outs. Forced to become a Lycaon, Tokuchi soon finds himself at odds with the team's owner, Tsuneo Saikawa. After Saikawa refuses to give him a reasonable salary, Tokuchi proposes a special contract: pitching an out will earn him five million yen, but giving up a run will cost him fifty million. With every game having the potential to either make or break him, Tokuchi must outwit all who stand in his way.

The seemingly unimpressive Saitama has a rather unique hobby: being a hero. In order to pursue his childhood dream, Saitama relentlessly trained for three years, losing all of his hair in the process. Now, Saitama is so powerful, he can defeat any enemy with just one punch. However, having no one capable of matching his strength has led Saitama to an unexpected problem—he is no longer able to enjoy the thrill of battling and has become quite bored. One day, Saitama catches the attention of 19-year-old cyborg Genos, who witnesses his power and wishes to become Saitama's disciple. Genos proposes that the two join the Hero Association in order to become certified heroes that will be recognized for their positive contributions to society. Saitama, who is shocked that no one knows who he is, quickly agrees. Meeting new allies and taking on new foes, Saitama embarks on a new journey as a member of the Hero Association to experience the excitement of battle he once felt.