This is one of those series that make you wonder why on earth you had put off reading it for so long, because once you begin reading, you simply cannot stop. It was a little confusing and slow at the beginning, but once the story really kicked off, I was completely hooked. The art is a bit peculiar and was part of the reason why I had picked up at the bookstore so many times only to put it down again, but it's just a matter of adjusting. It's too good a read to put aside for that reason.
The Cliffsnotes version of the story - Mahiru has a recurring dream where she hears a haunting song about the doomed love story between a princess and a demon, and when she meets a few members of the Lunar Race, finds out she's integral to their desperate bid to retrieve the "Tears of the Moon," which will restore their powers and save their kind. I can't completely shake off the feeling that there have been similar stories, but it's interesting all the same. Watching Mahiru work with Mitsuru (a tengu), Nozumu (a vampire), Misoka (a fox demon) and Akira (a werewolf) to find those precious gems and fight off their arch-rivals makes for a great blend of action, adventure and romance.
My only complaint is that there's actually too much plot for a measly 6 (short) volumes. There was a lot of necessary build-up, backstory and time covering the early stages of their journey, but the most exciting parts from about the 4th volume onwards felt like a mad dash towards the finish line. It could've used at least 2-3 more volumes to settle the events at the moon palace, Shirogane's change of manner and Mitsuru and Mahiru's developing romance. That said, I loved what we were given of the latter; even though Mitsuru annoyed me at the beginning, it was adorable how different he was once he had resigned himself to his feelings.
Despite the issues with the pacing and the not-the-best art, the combination of a great story with an interesting cast of characters (as well as a resolution that should please all fans of happy endings) makes Crescent Moon a must-read.