Upon first impression, Ibara Naruse and her companions Aoi Fukasaku and Taeko Nomura seem like your average high school students. However, their destination, the path they take, and the state of their surroundings are anything but ordinary. The trio treads deeper into a desolate version of Tokyo, ravaged by a nuclear disaster two decades prior. As part of the Dispatch 3rd Special Force Coppelion's Health Care team, Ibara, Aoi, and Taeko have the support of the Japanese Ground Self-Defense Force (JGSDF) and Colonel Onihei Mishima as they search the barren streets for survivors. The girls' daily routine includes locating any remaining humans and taking them to safety on JGSDF helicopters. As their mission progresses, Ibara and her buddies begin to question their own humanity, particularly how they can survive without any protective equipment in the hazardous environment of Tokyo.