In a world still shaped by an ancient conflict, Hayato, Chihiro, and Suzuna spend their days confronting and containing disruptive forces that threaten everyday life. Though they harbor their own ties to the vanquished side of that long-ago struggle, their efforts are aimed at fostering coexistence rather than conflict. When they learn that the entities sealed deep in the mountains centuries earlier may soon awaken, the three decide to journey to the remote site and prevent any return to chaos.