In the year 2016, a catastrophic incident at the Odaiba nuclear power plant contaminated the city with radiation and turned Tokyo into a ghost town devoid of life. 20 years later, Japan still struggles with the environmental consequences of that fateful day, and actively looks for survivors using Coppelions: genetically-engineered, radiation-resistant girls who scour the streets when SOS calls occur. With military support and funding to back them up, these young ladies continue to explore Tokyo and discover just who, and what, managed to survive.