Tokyo Swordia, previously called Tokyo Metropolitan, has been governed by the "Swordie" for 70 years since the Third World War. These Swordie are natural-born swordswomen with an attraction to blades; they more or less rule the country and are regarded as upper-class members of society. To raise his own social status, Kurou, a human, starts attending a swordsmanship academy, surrounding himself with Swordies on a daily basis. How will he fare in combat against those born to fight?