After more than three years of waiting, anime enthusiasts finally have concrete information which would confirm that the much-anticipated "Attack on Titan" anime series is indeed going to have a second season.

Last year, a fan posted a trailer of "Attack on Titan" season 2. The clip didn't have the best quality because the fan apparently recorded the video when it was released at the last part of the "Attack on Titan" live movie showing.

The trailer revealed how Survey Corps squad leader Hange Zoe and a bunch of members of the militia found out that a titan formed the foundation of the wall. Pastor Nick came running, and he told everyone to cover the titan up, so sunlight wouldn't get to it. The squad leader was enraged that the pastor knew about this and feared that the entire wall in the inner gates could be filled with titans.

Season 2 might finally reveal the mystery of the titan inside the wall. If this mystery unravels next season, perhaps the militia will find out that the bigger enemy is lurking within the walls that they have been guarding.

According to reports, season 2 might reveal the true identity of Survey Corps member Krista Lenz. The character is really Historia Reiss, the youngest child of Rod Reiss. The Reiss clan were the original royal family within the walls of Sheena. According to the report, the family owned the "Coordinate," which was defined as the "Titan's power."

Hajime Isayama is the mangaka or author behind "Attack on Titan." Like most mangaka, Hajime writes and draws the anime. The manga was launched in 2009, but the franchise branched out and evolved since then. "Attack on Titan" now has four spin-off manga, two live-action films, one anime season released in 2013, and a spin-off anime series "Attack on Titan Junior High."

The second season of "Attack on Titan" is expected to launch in the spring of 2017.