About a month ago... a pandemic caused by a mysterious disease broke out. The mysterious disease has no official name, but some call it the "Zombie Disease." The symptoms are exactly like a zombie: the brain ceases to function, the self is lost, the skin rots, and the infected attack people. It is not airborne, but if bitten, the victim suffers from a high fever and becomes infected within a day.

Due to the pandemic, the government and social functions began to collapse, and utilities like electricity, water, and communications became unstable. In the midst of the pandemic... people in a panic are said to be making a fuss online or suffering mental breakdowns. In various places, communities have formed, using schools or buildings as bases to set up barricades and survive, while others likely continue to huddle at home, trembling in fear.

In the midst of all this, five people were on the move... they were in a supermarket in the city center. The electricity in the supermarket was broken, making it dim; food was almost exhausted, some items were rotting and smelled terrible, and there were bloodstains and traces of where zombies had likely been.