The second season of "Attack on Titan," originally known as "Shingeki no Kyojin," is rumoured to premiere by the second half of this year. However, it might take some more time for the new episodes to air as the creators have decided to follow closely the events in the original manga series.
The "Attack on Titan" manga creator Hajime Isayama and anime director Tetsuro Araki have agreed that in order to continue the anime adaptation, the original "Shingeki no Kyojin" manga must have to be at least four story arcs ahead of the anime series.
The current storyline of the anime series is just two arcs ahead of the climax in Season 1, and it seems that the production team will have to wait for a while before continuing the anime story as the manga is slowly, but steadily, progressing.
As reported by Crossmap, if the creators of "Attack on Titan" anime series follow the story of "Shingeki no Kyojin" manga closely, it might take more than the expected time before fans get to see the Season 2 continuation, as the current events of manga will need be added to the upcoming season.
If the upcoming season will remain faithful to its manga counterpart, the fans will get to see Eren Yeger and the other members of his squad trying their best to defeat the Titans.
According to Parent Herald, the second season will be more action-packed than the previous one as the lead characters will be adapting battle movies from the manga to fight against the Titans. The new episodes will showcase the events from manga like abduction of Eren and Commander Erwin Smith loosing an arm.
Some speculations also suggest that in the next season, Levi Ackerman, one of the most popular characters of the series might get killed.
Isayama has also hinted that Ymir will have a much significant role is Season 2 than the previous season.