A must read, not only for the great story it tells but also for the short amount of chapters it has. So even if you dislike it, it's not a waste of time (Imagine reading a 400 chapter manga that you didn't like very much).
Story: The plot is as interesting as the characters that drive it. Really interesting concepts and world building (albeit, little world building considering this takes place in modern japan), with a understandable story that doesn't get ultra confusing. The main negative is the amount of chapters it has. It doesn't feel rushed or anything, but it has the potential to be more than it is right now. They could have introduced a lot more wacky and interesting characters with cool and intriguing cases to be solved by the duo of protagonists.
Art: Absolutely fantastic art by the same artist that gave life to the world of Deadman Wonderland, Kataoka Jinsei. The main positive of this sectionare the character designs and expressions. Top Notch art from a Top notch artist.
Character: A cast that will catch your attention instantly, interesting and likeable personalities, traits, and reasonings. Would be nice if they had more growth, but the amount of chapters makes it not possible.
Enjoyment: You can read this manga in one seating due to how short it is, so you won't feel bored while reading it, it mantains the readers interest from beginning to end.
Overall, a good short manga that is able to present a nice introduction and conclusion without rushing anything or feeling forced. The amount of chapters already make it an easy read.