Mythical Detective Loki Ragnarok (2003)

Loki is the Norse god of mischief. Banished by Odin, Loki is forced to take the form of a human child. The only way he can return to the realm of the gods is by collecting the evil auras which take over human hearts. Forming a detective agency specializing in paranormal things and aided by his loyal companion Yamino and soon joined by a human girl named Mayura who is unusually obsessed with mysteries. The adventures begin and are far from slowing down.