I watched the first episode of this earlier and all I can say is, wtf? Is there some secret previous season I don't know about? (afaik there isn't)
The anime starts at around chapter 30 of the manga and just throws you right into the middle of the story and expects you to already know who these people are and what's going on. There's absolutely no explanation of who the characters are or why they act the way the do or why they're doing the things they're doing. Absolutely nothing.
It was decent episode, but if I hadn't already read that far into the manga I would have had absolutely no clue wtf was going on and probably wouldn't watch any more of the show.