A lone maiden with the ability to perceive the eminent future traverses to the abandoned island Haikyo with a single task, to exterminate every Kogori Demon that inhabits the place.
On this island, clad in ambiguity as extensive as the mysterious electric towers erected about the premises, lies a meager population, and these ghastly apparitions, exclusive to the island, birthed from the strong desire of their hosts.
Immediately upon arrival, Mimei met Yato, a man who shares her same goal, albeit for a very different reason. That is, to instead consume these demons. This story tells of how these two parties, borderline foes, yet still companions, passed their days side by side.