An ordinary, small island—Sheephead Island.On this island stands a prison that houses only the most dangerous criminals. Takamiya, the island's resident police officer, was leading a peaceful life until one day, the alarm for a prison break echoed across the island.As the panicked townsfolk were brutally massacred one by one, the police played their final trump card: A high school girl named Yuka, also known as "The 13-Killer." In an island where the survival rate is 0%, can this merciless girl hunt down the demons that stalk the land?A blood-soaked tale of madness and an unprecedented conclusion await in this harrowing survival suspense!