I can't believe you people haven't even heard of this series....it has even been posted about.....What the heck? XD
OH well....you can join the guild so you can learn more about it....anyway, it's a really violent anime and it started off as a eroge. Let's see....ummmm....yeah it just got licensed by Geneon so look for it. Even though it'll probably be watered down.
I'm not going to post the link to the guild here....that's too much like commercilizing so PM if you want to join the Higurashi guild....it also has Shuffle in it for you that that interests.