Sorey is a human youth who grew up among the �seraphim� (tenzoku), spiritual beings invisible to human eyes. He believes in the folklore that every human was able to see the seraphim long ago and dreams of unraveling the ancient mystery to make the world a place where people and seraphim can live together in peace. During a visit to the human capital, he becomes embroiled in an incident during which he pulls out a holy sword imbedded in a rock and ends up becoming a �Shepherd,� one who casts away calamity from the world.