The second season of "One Punch Man" has not been announced yet, but has been already confirmed to be in the works. However, it has not stopped curious fans and the media to attempt to fish out glimpses of the story by asking the anime's director Shingo Natsume.
Though there have already been rumors about Saitama suffering his first defeat at the hands of hero-killer Garou, it is notable that the anime adaptation of "One Punch Man" does not necessarily follow the manga. Garou is a skilled martial artist, and a former student of Band, an old man who was introduced during the first season.
In an interview with Inquisitr, the director from Madhouse studios Natsume expressed his priority to entertain audiences on an international scale, which could probably be the reason why the anime does not closely follow the manga. Natsume's take on the animated version of "One Punch Man" was inspired by the feedback he got from one of his previous works released in 2014 — "Space Dandy," which is an action comedy.
After the reception "Space Dandy" received from international fans, he then began to think about his work in order to apply the same formula that worked for the show — which is what happened to "One Punch Man." So far, the results have proven to be successful. Given the feedback of "One Punch Man," fans can expect the show to stick more to the rhythm of the anime rather than the manga.
Another popular rumor is that Speed O' Sound Sonic will be able to train enough to be able to contend with Saitama. Sonic was introduced in the first season possessing incredible speed — which was unsurprisingly surpassed by Saitama. However, the manga has shown Sonic and Saitama crossing paths once again.
There hasn't been a conclusion yet regarding this encounter, but it has surely fired up the fans to speculate more on who Saitama's next adversary is going to be. But then again, if Natsume does not stick to the manga's script like most anime, then it is anyone's guess at this point.
"One Punch Man" season 2 will air some time in 2018.
