Infinite Stratos (インフィニット・ストラトス) is a Japanese light novel series by Izuru Yumizuru with illustrations provided by Okiura (original MF novels) and CHOCO (new Overlap novels). As of October 2013, 7 volumes have been published by Media Factory under their MF Bunko J label. From volume 8 onwards, the novels are published by Overlap under their Overlap Bunko label. A manga adaptation by Kenji Akahoshi was serialized in the seinen manga magazine Monthly Comic Alive from May 2010 to July 2012 with five volumes published under their Alive Comics imprint. A 12-episode anime adaptation aired in Japan between January and March, 2011, and an original video animation (OVA) episode was released on December 7, 2011. The anime is licensed by Sentai Filmworks in North America, and they released the series on April 10, 2012. A second series aired from October 3, 2013 to December 19, 2013.
In the near future, a Japanese scientist engineers a powered exoskeleton called “Infinite Stratos” (IS). Possessing technology and combat capabilities surpassing those of any other arms system, the IS threatens to destabilize the world. Faced with such an overpowered weapon, the nations of the world enact the “Alaska Treaty”, which states that IS shall never be used for militant combat, and that existing IS technology must be equally distributed to all nations, to prevent any one nation from dominating the others. The introduction of the IS does, however, have a major effect on society. As IS can only be operated by women, there is a shift in the power balance between men and women, where women now dominate society over men.
Ten years after the IS was initially introduced, the world has entered a new age of peace. The peace is shattered, however, by Ichika Orimura, a 15-year-old Japanese boy. In a coincidental run-in with a hibernating IS suit, it is revealed that he possesses the innate ability to operate an IS; the only male able to do so. Realizing the potential, the Japanese government forces the bewildered young man to attend the prestigious Infinite Stratos Academy, a multicultural academy where IS pilots from all over the world are trained. Thus, he starts a busy high school life surrounded by girls training to pilot IS.