Humanity once gained Patia, a flawless energy source that made every person self-sufficient in food and fuel. Trade and transport faded away, and civilization stopped advancing. Now genetically modified plants blanket nearly all the land and hinder anyone who travels. Cient, leader of a fortress city, sets out with his daughter Ruri to dig up the lost Patia technology. When Ruri is separated from her father, a giant humanoid weapon from the old era attacks her. She is rescued by Tekuni, a girl roaming the world as she trains to become a Wazabito fighter.