The story begins in Japan of the 1920's... In this world, after the great demon war, humanity took to technological development, and steam technology reigns. But the world lives in fear of the return of the demons, and strategically important Tokyo will be the city where the battle will begin. But humanity is not going to sit idly by - an internationally agreed upon, semi-secret organization has been formed to defend Tokyo, and only the best and brightest will join its ranks. At the heart of this organization is the Uba Spirit Armor, suits of power armor developed by Kanzaki Heavy Industries and powered by the operators' own spiritual energy. Only one problem: No one in the army seems to be up to the task. But, fortunately, the granddaughter of old man Kanzaki seems to have more than enough spirit energy to go around, and she's well versed in some pretty impressive fighting techniques to boot.