On the small, unremarkable island known as Sheeptop Island, a massive prison stood tall—one that held only the most vicious criminals.

Officer Takamiya, stationed there, lived a quiet and peaceful life… until the blaring alarm of a prison break shattered the calm.

As panicked islanders fled, they were brutally slaughtered one after another. With the situation spiraling out of control, the police unleashed their final trump card.

A high school girl named Yuka—also known as “The Thirteen-Killer.”

On an island where the survival rate is zero percent, can this merciless girl hunt down every last monster?

A brutal survival suspense that will leave you trembling—
soaked in blood, driven by madness, and ending far beyond all expectations.