Not the darkest thing I have ever read, but still dark enough to enjoy. Every chapter tends to end with a sense of irony, especially toward the beginning of the series. So far, a few of them have even had the potential to be fairly disturbing (probably moreso for some than others). Fair warning: Nothing seems to end well in this manga, although a new main character introduced a few volumes will provide occasional comic relief later on. The world and the characters are introduced and expanded on gradually, as a sort of suspense that really fits in with this manga's style. Another thing about NightmareInspector is that the art is absolutely wonderful. I love the artist's coloring style for the covers, and the amount of detail -- the inside of the manga tends to be full of detail too, and the backgrounds especially are a lot of fun to look at.

I've been buying the volumes in real life as apposed to reading chapters online. I WILL finish this series someday, because the story only gets better the further you go along (there is, eventually, an underlying problem with being a baku mixed in with the series's episodic format).