Once there was a story about a boy and a Keyblade, who came (rather late) into a war and saved the universe.
This is not that story.
This is instead a story of the place where the war began, before the creatures called the Heartless appeared. Hollow Bastion is a largely peaceful world with, somewhat oddly, a surprisingly strong military force known as SOLDIER under the command of the king, a mercenary force known as SeeD that is less officially sanctioned and supervised, and a small, elite group of men and women called the Turks that personally protect King Ansem and do his bidding. Some would find this odd - the military in particular, with no wars to fight or uprisings to put down, is almost more of a police force than an army - but on Hollow Bastion the purpose of the organizations is rarely questioned; they provide thousands of jobs, and it's simply the way things have always been.
Only recently have issues begun to arise...
For reasons no one is quite sure of, men and women have been disappearing - most of them having belonged to SeeD or SOLDIER. The formerly low-risk job of being a SOLDIER has begun to look outright dangerous, if only because of the rising statistics of people vanishing from their ranks, and the enrollment of children into the SeeD schools has dropped alarmingly. No one is sure what is happening to the people that vanish; no traces of bodies are ever found. But none ever return.
Some conspiracy theorists, of course, would have you believe that some mysterious force is working to undermine the military strength of Hollow Bastion in preparation for some sort of hostile takeover, but obviously that's ridiculous...
As you may have gathered, this is a Kingdom Hearts AU RPG, set on Hollow Bastion about a year before Ansem gives his body over to darkness and unleashes the Heartless upon the universe and intended to chronicle the events of that year and afterwards. The game is NOT going to stick strictly to what would have happened in canon, which is where the AU part comes in. For one thing, ALL CHARACTERS AND GAMEPLAY WILL BE RESTRICTED TO HOLLOW BASTION. That means no other worlds will be open for play. HOWEVER, even though Hollow Bastion is theoretically a Final Fantasy characters-only world, characters from any and all fandoms will be accepted - you simply have to work their stories into a Hollow Bastion setting. (More on the world here.)
This game is also going to put a lot of emphasis on SOLDIER, SeeD, and the Turks as organizations that will be most often and most directly effected by the changes undergoing their world. Civilians are certainly open for play if for some reason you'd rather not play as a character from any of those groups, but they'll probably have less to do unless they're in some way connected to a character from one of these organizations, so consider yourself forewarned.
Speaking of those organizations, there are various rules for applying for characters from them. Some jobs (like low-ranking SOLDIERs) are open to everyone, whereas some (like the Turks and SOLDIER, First Class) are rather restricted because they're SUPPOSED to be exclusive organizations. It will help your case immensely when applying for a character in a restricted job that you have a good argument for your character having that job. (More on ranks here.)