Lagrange: The Flower of Rin-ne (2012)

Madoka is the lone member of her school's Jersey Club. She is one day recruited by a mysterious girl named Lan to pilot the robot "Vox" and protect her city from space invaders. They are joined by a third girl, Muginami, who has a different goal than Ran. Meanwhile, they still don't know their enemies' true goal, or what "Rinne" might be.