The story is set in a world that heads toward destruction every hundred years or so. The protagonist, Clear, chosen as the hero to save the world, encounters Towa, a saint offered as a sacrifice for the world's sake. Although Clear is initially startled to discover that Towa is actually a man, he is drawn to Towa's personality and begins to worry about the future where he must kill him. Will Clear choose Towa, or the world—or perhaps, both?