The show is based on a manga written by Gamon Sakurai, having, as of writing this review, 14 volumes and slowly coming to an end (unfortunately). The series represents the story from the comics very well, the casting is also great. The CGI is alright - at first it may look odd, but after a while it doesn't stand out at all. The story itself is about a young student aspiring to be "an outstanding member of the society" whose dream has been destroyed after being crushed by a truck (yeah, truck-kun, always there to help). He revives after the accident and is therefore declared an ajin. Ajin is an immortal humanoid disowned of any human rights. Everybody wants to capture him, as there's a bounty on his head, allegedly. Kei's cold and asocial personality together with his wits, logical thinking and incredible memory gives the viewer a protagonist that will always surprise them. Other characters in the story are also very interesting, so even if you don't like the protagonist I encourage you to watch it for Tosaki, Izumi, Sato or Tanaka. And if the anime won't be enough, there are 14 volumes that give the world and the characters even more opportunity to shine.
Please go and watch it if you're into thriller/terrorism themed shows. It's really great,. 5/5
Edit: okay, so I'm rereading the manga and the art is so good. I strongly recommend to go and read at least the first five volumes. You won't regret it