For high-schooler Yoko Nakajima, life has been fairly ordinary—that is until Keiki, a young man with golden hair, tells Yoko they must return to their kingdom. Once confronted by this mysterious being and whisked away to an unearthly realm, Yoko is left with only a magical sword; a gem; and a million questions about her destiny, the world she's trapped in, and the world she desperately wants to return to.