The latest update for "One Punch Man" Season 2 is that there's a possibility that the season will be based on ONE's  "Hero Hunter" arc. There are also rumors that the season will feature a hidden story arc that will reveal Saitama's past.

According to University Herald, there are reports stating that season 2 will be following ONE's story about Garou, who also possess God-like strength, hunting down the heroes one by one. This could also mean that fans will get a chance to see Saitama and Garou slug it out.

Garou is a former student of Bang but was kicked out of the dojo for beating up his fellow students. He is a big fan of monsters, earning him the nickname "Human Monster", and he also hates heroes in general.

In one's "Hero Hunter" arc, Garou set out on a mission to eliminate each and every hero of the hero's association. He is doing this so that monsters can roam freely without any oppression and he hates heroes.

Garou doesn't have superpowers, but he has God-like strength. He's also a skilled martial artist, learning from Bang before he went rogue.

Aside from the "Hero Hunter" arc, the latest update of "One Punch Man" Season 2 will also be revealing something about Saitama's past. It is rumored that the season will reveal Saitama's inspiration in becoming a hero and the origin of his power.

However, the latest update of "One Punch Man" Season 2 also say there are rumors that a hidden story arc that will be featured. GameNGuide reports the hidden story arc would reveal a segment where Saitama's family was annihilated.

This is just a rumor, though, so it's not yet certain it will be in season 2. Furthermore, this story arc is not featured in the manga, so there's a big possibility that this story won't be in season 2.

There's no word yet on when season 2 will air. But updates of "One Punch Man" Season 2 are saying that show is set to be released sometime in 2017.