Zaphira City consists of 2 layers; the lower city and the upper city, which is a city floating above the lower city. The citizens of lower Zaphira are refugees that created their own society while being looked down on from the upper city.
The upper city's military, the ZMF, is coming down, and people don't understand why, but the local ZPD, "Zaphira Police Department," has already been dissolved by the ZMF.
You can follow the story on the channels below. If you are interested in seeing what has already happened, all ZMF episodes have been highlighted on my twitch channel!: https://www.twitch.tv/lunakasai