Ichika Orimura becomes the first male ever to activate an Infinite Stratos, a powered exoskeleton so dominant in combat that only women have been able to pilot one until now. Enrolled at the all-female IS Academy under his older sister Chifuyu, a legendary former IS champion, Ichika draws immediate attention from national-representative candidates, among them childhood friend Houki Shinonono and the British pilot Cecilia Alcott. Arena matches against them fill his first term as threats to the academy begin to surface.