IS: The Iron Blooded Orimura
After The attack in Germany, Ichika's twin brother(Madoka's as well); Gwynn Orimura, is picked up by an IS pilot: Mikazuka Augus. Mikazuka taught Gwynn to use her IS at a young age, but never let him fight using it. When the IS academy finds out about him the send Chifuyu to ask him to come to the academy.