Osuna is the top student at Kusanagi School of Magical Architecture, a national high school dedicated to raising professional magical architects of the future. Their job is to apply feng shui and other spiritual methods to architecture to exterminate fiends and demons in Tokyo, where the protective feng shui seal has been broken due to wars and urban development. Being raised by a spider fiend, Ozunu has always tried to purify monsters - but this causes clashes with his rival, Tsugaru, the heir to a magical architecture corporation.