In a world left devastated by a cataclysmic global disaster, a survivor awakens in the ruins of his school, now transformed into a desolate wasteland haunted by eerie phenomena and grotesque mutant creatures. The once-prosperous Blue Planet Civilization has been wiped out overnight, and survivors must now navigate the perilous Global Massacre Era, where all living beings undergo dangerous mutations.

Guided by an enigmatic old man, the protagonist discovers that he has become a Super Gene Awakener, granted unique abilities in this nightmarish world. Urged to endure for seven days, the old man offers him a dangerous proposition—to purchase Gene Magic Cores from the slain Mutant Creatures, plunging him into a deadly game-like reality he never anticipated.

With hope waning and uncertainty gripping him, he embarks on a harrowing quest for sustenance amidst the school's ruins, managing to scavenge enough supplies to survive. Soon, another survivor emerges, bringing new challenges and raising profound questions about the nature of their existence in this altered world.

As the days pass, he must confront terrifying mutations, unravel the mysteries of the Global Massacre Era, and make pivotal decisions that will shape his destiny in this treacherous new reality. Can he endure the impending horrors, unlock his true potential through the Super Gene Awakening, and triumph over the nightmarish trials that lie ahead?

C256 Let Them be Rats.