The Days Union is set in a dystopian future on a foreign terrestrial planet, the 'Prime Universe' within the Multiverse. Great_Day is the leader of the Day Operatives, a tyrannical and sovereign person who uses authority to rule over his city. The Day Operatives are cruel war machines who contain a darkness virus inside of them. They are under the absolute control of Great_Day, endowed with heightened and extraordinary abilities such as teleportation.