Another

Another is labeled as a horror anime, but it really is much more of a mystery thriller. It has several scenes of gore and I guess that's the reason behind the 'horror' label. Anyway, the mystery is handled just right in that it keeps you wondering. You'll want to watch the next episode immediately to find out what is going on in this classroom?

The main character is kept in the dark about the strange events that occurred in his classroom a long time ago and how it affects what's happening now. A mysterious girl with an eye patch is ignored by all the students, yet he is not told why. As the days pass and as people die he begins to unravel the mystery.

Although it doesn't have the most well developed characters, the mystery plot is more than enough to keep you engaged.