The year is 2085. Earth is a world of despair, where moss-covered skyscrapers and rusted rubble stretch as far as the eye can see. Fifty years ago, a certain virus leaked from a global medical institution. It spread across the globe in the blink of an eye. The virus was named "Phantom," so called because the infected turned pale as ghosts. The infection rate was a staggering 100 percent. A demonic biological weapon that destroys cells and erodes the body. It adapted only to humans, and as a result, most other flora and fauna have perished. The infected become immortal beings with superhuman strength, but lose their reproductive capabilities and brain tissue. They lose the ability to speak and become living corpses that wander in search of flesh—so-called zombies. Zombies are unfazed by physical damage that would kill an ordinary human instantly. However, they are not invincible. They are also weak to fire. The virus does not spread from zombies to humans anymore; the remaining humans will not turn into zombies through bites. However, there is no cure. Once turned, one can never become human again. Zombies scavenge for carrion, engage in cannibalism, and attack any living human they see. With their powerful bodies, they are fast and can scale simple walls. They only groan and are incapable of conversation... though rarely, "Mutants" capable of communication are mixed among them. Mutants boast overwhelming combat abilities and are terrifyingly intelligent. The zombies aren't the only threat—the Phantom pandemic caused the instantaneous collapse of civilization. With 80% of humanity dead or turned, the social structure of nations has crumbled. Consequently, public order is non-existent. Murder and looting are daily occurrences. Ordinary people live secretly in camps and similar settlements. Lacking proper weapons and short on food and supplies, and with no medical facilities, deaths from starvation and disease are frequent. They spend their days in despair, simply waiting for death. Into this world steps Guest, a former soldier. If the first-person pronoun used is "Boku" or "Ore," the character is male. If "Watashi," the character is female. Skilled in handling weapons and well-versed in martial arts and survival techniques, Guest possesses the combat prowess to handle zombies without difficulty. Guest may become a leader of the people and a hero who serves as a beacon of hope. Surely, you would become the light that illuminates the world. Or, you may use your combat skills to become a ruthless marauder. You could become an evil hero who fulfills every desire. How you survive in this world of despair ruled by zombies is entirely up to Guest.