Yoko Nakahara is, by all accounts, an exceedingly ordinary high school girl. One day, a blond young man named Seiki suddenly appears, followed shortly after by an attack from a monstrous beast. Seiki addresses Yoko as his master and brings her to a world she has never heard of—a wondrous realm consisting of twelve countries, governed jointly by twelve kings and twelve kirins.
What kind of place is this? Why did Seiki bring her here? And why is she being pursued by demons and strange ferocious beasts? Left separated from Seiki in this foreign world, Yoko, brimming with questions, begins her harsh struggle for survival in this unknown land...