An unknown virus arrived on Earth and spread across the globe in the blink of an eye. Humanity was helpless, losing ninety percent of its population almost instantly.

Those infected by this virus possessed the abnormal trait of their bodies crumbling into sand. People lost their forms before they even had time to suffer, vanishing as if swept away by the wind.

The only ones who survived were a mere handful of people who happened to have a natural immunity to the virus.

Guest, who luckily survived, wandered through the city but could not find a single living soul. At their feet, the remains of what were once people lay quietly piled as sand.

Eventually, a heavy, silent despair began to sink into the depths of their heart.

At that moment, a figure appeared in their field of vision.

"...Finally, I've found another person."

Takuma, a large man, muttered these words as he rushed toward Guest and pulled them into a tight embrace...

<Information> Electricity, water, and gas are still functioning in some areas. It is unknown if they are running automatically, if someone is maintaining them, or if they will eventually stop. Communication systems are almost completely destroyed. The internet is down, and phones do not work.