I grew up with an interest in Norse mythology, so when I saw an anime with both 'Loki' and 'Ragnarok' in the title, I was immediately interested. Reading the description I knew that not to expect too much of a connection to the old stories, but I thought it would fun none the less. I am glad I picked it up :)
Loki, the god of mischief, was cast from the world of the gods down to the human world. In order to return he must collect the spirits of evil that posses human hearts. The thing is, for reasons unknown, during his stay in the human world he is bound to the form of a child. In order to hunt down his quarry, he starts a detective agency and somehow manages to get stuck with a teenage girl named Mayura as an assistant. Things aren't going to bad for Loki, until the other Norse gods and goddesses start showing up trying to kill him!
The Nose mythology was my favorite part of this series, but I also enjoyed the plot and characters. Loki is an entertaining character and Mayura an endearing one. The supporting cast is large and diverse, and it is always fun when a new god is introduced. I think this series would be most entertaining for people who know a little bit about the myths and legends this series draws from. I showed it to one friend who knew pretty much nothing about Norse mythology, and she found it cute and entertaining, but wasn't all that thrilled with it. But my sisters, who are all familiar with the Norse gods, all really enjoyed it.
If you enjoy the series and decide to hunt down the manga, be aware of two things - first, the manga this is based on is actually called Mythical Detective Loki and Mythical Detective Loki Ragnarok is the sequel (which the anime has no relation too). Second, only the first two volumes of the second series are available in the US. For some reason, Singapore released an English translation of both manga series, and it is possible to find them on eBay. I liked the manga better than the anime, but after paying international shipping + the cost of the books, it is cheaper to get the anime!