A 2009 light novel series by Yumizuru Izuru and illustrated by okiura, later adapted adapted into a 2011 anime series by 8-Bit (with character designs by Kurashima Tomoyasu [artist #20030]) and a manga serialized in Media Factory's Monthly Comic Alive, illustrated by Akahoshi Kenji.
15-year-old Orimura Ichika is discovered to be the only male capable of piloting an Infinite Stratos (IS), a powered exoskeleton system (with weaponry so advanced the world's nations agreed to ban their military application) otherwise usable only by females. He is then enrolled into the Infinite Stratos Academy, where his older sister Chifuyu, herself a former ace IS pilot, teaches. Along the way he meets his childhood friend, a British aristocrat, his other, Chinese childhood friend, a French transferee, and a German super-soldier, each vying for his affection.