A year from the future.
Humanity began to decrease under the influence of viruses and nobody could find a cure for this. The most recent experiment in a lab failed, and the virus managed to leak out of the lab.

So, would humanity be left to its fate in these relentless viruses? No.
Thanks to an AI developed called Nerva, a space station has been established outside of the world. All the hopes of humanity are reawakening in Nerva.

Welcome to the Nerva Space Station.