Characters wake up with amnesia in a dorm, where they have a profile (that may or may not be correct) which tells them their unit name, their position in the unit (currently blank and flashing) and whatever else their players decide to give the character. It might be true! It might not be. It's highly incomplete, even if it is correct.
Maybe they suspect something! Maybe they don't! They have amnesia, after all. They probably should suspect something is up, though, by the ubiquitous surveillance cameras around every corner. Or the fact the city is obviously fake—most these buildings don't even have doors? As it turns out, characters have been scouted for stardom and placed in units to compete for the favor of the audience. Go head-to-head in death games or make use of your unit's performance gimmick on the side in order to rack up rewards in the form of points!
And points are very important. Win one game, get 500 points. 500 points? That's enough to buy one memory back. Or five new outfits! You know, your call. Showing up but not winning still gets you 100 points, so you can still save up even if you're on a unit full of hopeless losers! In any case, do your best, everyone, and show the cameras your good sides!