It is the story of three worlds separated into three parts: The upper one: called high heavens, where the winged people live, the descendants of ancient dragons. The middle one: the land where humans, elves, orcs and other inhabitants live. The bottom one: called the neutral lands where spirits and evil creatures live. After certain events, the worlds decided to close their borders, only certain people can travel without permission. And if you travel without permission, you are executed.