In the whole world there lay a mythical creatures which have their own ecosystem and canot be considered part of the food chain. They also have supernatural powers and live together with humans. Ferry is one of the professional investigator, who researches the connection between the creatures and humans and is called a Genjuu Chousain (Mythical Beast Investigator). The story starts when a flying reptilian dragon (Wyvern) is attacking a village, and a Girl dispatch on the quest to research and investigate Wyvern and other mythical creatures.