Thousands of years ago, mankind was at the height of its glory, an advanced civilization extending into the far reaches of space. To defend against its galactic enemies, mankind developed giant humanoid robots called "Vox," never anticipating that the powerful robots would lead to the destruction of their own civilization. Fearing their infinite power, the Space Federation known as Polyhedron hid away the existence of the Vox and Earth itself from the rest of the galaxy. Now, the Vox are a mere legend, and in Kamogawa, Japan, robots are the furthest thing from Madoka Kyono's mind. She's an energetic high school girl who just wants to help people in need. But Earth is under threat once more, and when a mysterious girl named Lan asks Madoka to pilot a resurrected Vox robot, her life will never be the same!