Sora Morimoto, a girl who live in Neo Draconis, meets a mysterious gatekeeper inside a space train with no memory where she came from or who she is. Sora gives her the name Xion. Xion asks her to help her stop an unknown threat lurking in the shadow. Sora agreed to help her with her mission by leaving Neo Draconis. Sora ran into a girl named Rinka Narukami, a girl who live in Inazuma who was sent on a mission by the master of the Inazuma and join them on their quest.