Ibara Naruse, Aoi Fukasaku, and Taeko Nomura, seemingly ordinary high school students, navigate through a Tokyo devastated by a nuclear catastrophe two decades prior. As members of the Dispatch 3rd Special Force Coppelion's Health Care team, aided by the Japanese Ground Self-Defense Force and Colonel Onihei Mishima, they brave the desolate city to rescue the few remaining survivors. Their daily mission involves evacuating these individuals via military helicopters. Yet, amidst their humanitarian efforts, Ibara and her companions grapple with a profound existential dilemma—how are they unaffected by Tokyo's hazardous conditions, prompting them to question the essence of their own existence.