It only took creator Murata Yusuke to say he will "work hard" to make "One Punch" season 2 happen for the fans of the manga to theorize on all the possible storylines that could happen in the series.

The first season had 12 had a total of 12 episodes. Because of "One Punch Man" season 1's massive success, there are talks that the next season would have more than 12 episodes which have been reported to premiere by December.

However, Otakukart estimates that a season takes about six months to two years to sketch and if that estimate is right, season 2 will not be able to premiere as targeted this year.

There are theories that the events next season would be a continuration of events that were introduced earlier on season 1.

One theory states that a villain who appeared in the first episode named Garou is the next season's main antagonist. Garou used to belong to S-Class at Rank 3. His backstory is that of a misguided youth who Silver Fang took in, trained and eventually exiled due to his evil doings. 

Another character rumored to have taken a darker path is Amai Mask, who will reportedly blame the Heroes Association for the sad fate of the city. Amai Mask, who belongs to Class A Rank 1 heroes file, is said to still be a protagonist in the first few epiodes before his anger consumes him.

Rumors about Lord Boros who Saitama defeated in the first season is also making rounds online. Talks have it that despite previously conceding to be only half as strong as Saitama, he will do everything to succeed in his attempts to once again be known as the strongest of them all.

If that's true, the series will see more evil allies as Lord Boros lost his arm in a battle with Saitama when the previous season ended.