Tokyo 24th Ward
In the 24th Ward, located in Tokyo Bay, residents are able to enjoy a safe life thanks to "Hazard Cast", a system that predicts and assists victims of accidents. Three friends, Ran Akagi, Kouki Suidou, and Shuuta Aoi, who have been nicknamed RGB due to the colors of their hair, had a tragic experience with the limitations of the system. A year after Suidou's sister, Asami, died in a school fire, the trio was reunited for a commemoration for the victims. Here, all three of them received a mysterious phone call with Asami's voice, along with visions of two future outcomes. Refusing to accept these predetermined outcomes, they choose instead to confront whatever lies ahead in order to protect the 24th Ward.