Deadman Wonderland Opening - One Reason
Deadman Wonderland is a prison and amusement park where prisoners perform dangerous shows for visitors. Although visitors think these dangerous actions as illusions and prepared set ups, the truth is that every prisoner should risk their lives and even die to win those deathly games in order to survive in this prison.
The anime is on the "bloody" and "violent" side of the spectrum and has 12 episodes. There are some dissimilarities between the anime and the manga but for most people it's worth giving a try!