Percival lived with his grandfather atop God's Finger - a secluded retreat beyond the clouds. Despite his contentment with their simple existence, Percival couldn't help but yearn for a more thrilling life. His mundane existence turns upside down when a stranger, who seems intimately tied to him, destroys his world. With no other choice but to pursue the culprit who wrecked his life, Percival sets off on a high-stakes journey alone. As he navigates this dangerous adventure, the sheltered teenager begins to realize just how much he doesn't know about everyday life, but takes comfort in the companionship of newfound allies. But what will they do when they discover Percival's fate is inexorably tied to the destruction of the world?