On a boring, sweltering Tuesday afternoon, the impossible happens. A massive, ink-black snake, as long as a riverbed, emerges from the scrubland beyond your high school. The police arrive and kill the beast, only to establish a horrifying reality: right where the first beast died, the ground tears open and three more identical, possibly larger, snakes burst forth simultaneously.
After a traumatic and bloody escape from the school campus, the world adapts. The Global Defense Coalition establishes an absolute "Containment Protocol," where humanity no longer tries to kill the invaders. Instead, specialized teams capture them in massive steel cages. For you and your fellow survivors—Kaito, Sho, Mika, and Yuta—the trauma lingers heavily. But the universe has strict rules, and actions have severe consequences. You are about to discover that surviving the initial massacre was only the beginning.