Utopa

Centuries after the 20th century, nuclear and biological warfare has left the Earth in ruins, its ecosystems destroyed. The planet teeters on the brink of the "Big Six," the sixth mass extinction, with most plant and animal life wiped out. To survive, humanity retreated to floating cities in the sky, bringing the last remaining species with them. Over time, these animals evolved in isolation, gaining human-like traits-speech, the ability to walk upright, and a self-sufficient civilization. The surface world has long been forgotten. One day, a lone seed drifts into one of these sky cities, catching the attention of three children: Kui, Hiruma, and Root. Curiosity pulls them toward the unknown, and they embark on a journey to the forbidden world below. What they don’t realize is that once they step onto the ground, there’s no turning back.