Japan engineered an armed powered exoskeleton "Infinite Stratos" (IS) and it became the mainstream of weapons. Since only women can operate IS, women dominate the society over men. Orimura Ichika is a 15 year old boy and accidentally touches an IS placed in the IS pilot training school. He is found to be the only man who can operate IS and forced to enter the training school. Ichika's busy school life surrounded by girls has begun.

Note: The light novel stopped publishing on 2011 and resumed its publication a year later under a new label, Overlap Bunko. Due to this, the light novel changed illustrators, with CHOCO being the new illustrator of the series.