Katsuya Shiga

Long ago, a war was waged between the forces of darkness and light as Dark Brings--stones containing dark power beyond human ability--put the world at risk with their destructive force. In order to stem the tide of darkness, a lone swordsman used holy power known as the Rave to destroy the source of every Dark Brings. The resulting explosion, which came to be known as the Overdrive, destroyed a tenth of the world; fragments of the Rave were scattered throughout. (myanimelist.net)

There is a tiny island floating on the other side of a distant sea. Strange animals, still unknown to humans, live there. One of the island's children, Paroru, comes across a photo of the human world one day, and fascinated by this beautiful wonder, breaks the rules and rushes out of the island. Paroru and others are surprised and excited to see the human world for the first time. However, unforeseen pitfalls await them there... Can they safely reach their journey's destination?