Aoba is a young girl who loves building robot models. She lived alone with her grandmother until her grandmother passed away. Shortly afterward, she is kidnapped and taken to a secret base, where she discovers a huge robot. Piloted robots battle the Ancient-Jinki in The Grand Savanna, but the true meaning behind the fights remains hidden. Aoba works hard at the base so that one day she can pilot one of the robots and uncover these secrets.