Once upon a time, in the city of Uranopolis, lived the Winged People, a race capable of flying. But after losing a battle to humans, they gradually lost their ability to fly. Xuelie, a royal descendant from the Winged People, begins a search for the magical Naga Pearls in order to destroy humans and avenge the blood of his peoples.
When Ni the street punk, Gali the human prince, and Heiyu the Winged detective accidentally lay hands on a mysterious box containing the Naga Pearls, they find themselves hunted down by Xuelie. After they have lost the pearls to Xuelie eventually, they decide to team up and rush back to Uranopolis to thwart his atrocious plans.