This is a great graphic novel series. The characters are very enjoyable, the art quite nice, and the mythology usage is simply fantastic. I love how Watase managed to merge both Western and Eastern traditional myths of the watermaidens/swan princesses (the kind where if you steal their clothes, they have to stay) along with modern technology. My fave Watase series.
This is a great series of 14 books. There is a nice balance of action and fighting with Japanese mythology thrown into the mix. There are parts that will make you want to scream, other will make you laugh, while the rest make you cry.
By the time you read the last book in this series, you'll be wishing that it hadn't ended. If you are a fan of Yu Watase's other manga, then this is a must read.