The story begins with Izumi Hayato running to be student council president. But when a beautiful girl swings in promising the liberalization of love while flinging condoms into the audience, he ends up losing to her and becoming the vice president. At the student council meeting, the newly-elected president invites herself over to Izumi's house, where she promptly announces she is to become Izumi's wife thanks to an agreement—facilitated by alcohol—made between their parents when they were only 3. (Source: MAL Scanlations)

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?

Short anime specials included in the One Punch Man 2nd Season BD & DVD.

The shorts tell the story of two twin princesses, Berry and Flora, whose mother died giving birth to them. The two grow up until their father chooses Berry to don the title of Onaka Hime, or Stomach Princess, who is endowed with the power to heal the kingdom's citizens of illness and make its women beautiful through using BifiX 1000. Flora is disheartened at not being chosen, yet continues her studies. When it seems Berry is yet unable to use the powers of BifiX 1000 to heal a woman who is ill, Flora steals the product to try to do it herself. When Berry finds out what Flora is up to, she takes the product back before Flora has a chance to try to use it. (Source: ANN)