In a town unsettled by a string of unexplained phantom assaults, students at Akitoshi’s school grow increasingly wary of supernatural rumors. An unfamiliar girl suddenly appears on campus, yet only Akitoshi finds her presence suspicious and decides to follow her after class. His search leads him to a material yard where Mikage stands threatened by eerie creatures called Yuragi, until the skilled fighter Ai arrives to drive them back. Left shaken by the encounter, Akitoshi questions whether Ai is an ally or an adversary in the growing danger.