In the advanced 24th Ward of Tokyo Bay, residents rely on the Hazard Cast system for safety, despite its limitations in preventing tragedies. When Suidou's sister dies in a school fire, friends Ran, Kouki, and Shuuta, known as 'RGB' for their colorful hair, reunite after a year of grappling with guilt and dreams. A mysterious call from the deceased Asami prompts them to confront a choice between two ominous futures. Determined to defy fate, the trio embarks on a journey of harrowing decisions to safeguard their community and unravel the enigmatic forces at play.