There's also A LOT of annoying Pizza Hut product placements in nearly every episode. This anime also has one of the most annoying anime character types in the medium: I'm talking about the character in law enforcement that is just useless and who's only purpose is to provide us with exposition.
The premise is interesting though, random mysterious 'gates' appearing in South America and Japan, the stars being replaced by fake ones, contractors enacting weird rituals every time they kill. Some story arcs are better than others, it's a mixed bag. It's episodic, but tries to provide some plot development in each episode. There's a cool British character named after my birthday: November 11.
Kanno's music is good as usual, she's sublime, but I was slightly disappointed to hear her strings aping Don Davis's Matrix style.
The main character of Hei was pretty interesting, not least for the fact that he's a Chinese main protagonist in a Japanese anime, but he looks cool in that mask too, and we watch him deceive people a lot, which is always fun.
Darker Than Black is let down by the writing. You know its at fault when you realise after 25 episodes they couldnt explain the main mystery of the tale; the reason why the world is the way it is; why the characters are the way they are; why we bothered to watch the anime in the first place. There's a difference between smart ambiguity and stretching an interesting premise so thin you cant even wrap it up at the end.
