Ep.1 Road to Hero
Air Date: 2015-12-04
A story about Saitama from when he still had hair and his only costume was a track suit. Several shops in Saitama's neighbourhood have gone out of business and the owner of the last one left needs his help.
Ep.2 The Shadow That Snuck Up Too Close
Air Date: 2015-12-24
A story set sometime between Mosquito Girl's defeat and Genos showing up to Saitama's apartment. Genos wants to learn the secret to Saitama's power and decides to follow him and to observe everything he does. At the same time, Saitama is convinced that someone is stalking him.
Ep.3 The Pupil Who Is an Extremely Poor Talker
Air Date: 2016-01-29
Jenosu it accidentally trapped in Don Pacino a little bit caught in the Mafia of conflict. Jenosu that are in a hurry the shopping asked the bargain in Saitama's to explain to Don Pacino, but ....
Ep.4 The Ninja Who Is Too Complicated
Air Date: 2016-02-24
Sonic strive to strict training muffled to the mountain, but had spent the days of troubled with nightmares to be a nasty blow to the groin from Saitama who suffered a defeat. Man of Matagi had seen such a situation. He is also "formidable enemy" in defeated in the past of the owner ....
Ep.5 Bang, Who Is Too Overbearing
Air Date: 2016-03-25
After the events of episode 7, Bang begins to spy on Saitama and Genos to gauge their abilities. Hopeful that his Water Stream Rock Smashing Fist martial arts is stronger, and that proving so will coerce Saitama and Genos to study under him, Bang invites Saitama and Genos to his dojo under the pretense of giving them free meat.
Ep.6 The Sisters Who Have Too Many Things Happening
Air Date: 2016-04-22
During a coincidental train ride, Genos and Fubuki are put to the test when an anti-Hero Association group plants a bomb on the train. *This OVA is half as long as a regular episode.
Ep.7 The Murder Case That Is Too Impossible
Air Date: 2016-05-27
The Heroes of the Hero Association goes to an "onsen" ret.eat unwind after the battle with the alien invaders, with a mystery afoot when one of the heroes get stabbed...Child Emperor investigates the murder of Zombieman.
Ep.8 One Punch Man 2nd Season Commemorative Special
Air Date: 2019-04-03
One Punch Man 2nd Season's commemorative recap special.