There’s this game called Fiasco where you and your friends come up with interrelated characters and proceed to tell a communal story together, guided by some dice rolls and other mechanics. While the story itself is important (and, as you might guess, is designed to end in disaster for most if not all involved), the lion’s share of the game is arguably coming up with characters in the first place and making sure they have things in common, such as a location, item, etc. Ties that bind. Things to live, laugh, and love over — and also bicker and even kill over.
This web woven before a Fiasco game even begins is similar to how some writers will tackle keeping track of the characters in their stories, whether that’s on post-its or a whiteboard or a computer spreadsheet. Who knows whom? Which characters are friends? How good of friends are they? Or the same question but applied to antagonistic tendencies? How did they meet? How long has it been since they last saw each other? Is there something else that connects them, and if so is it simple as a convenient MacGuffin? Or something deeper?
Not every writer does this much prep and not every character needs it: the horde of ninjas wants to kill the hero because Their Master Wills It. ‘Nuff said there, especially if that’s the kind of story you’re telling. But you certainly want to have some kind of handle on how your major characters will interact, even if their meeting remains hypothetical. With rare exceptions, people don’t show the same “face” to their boss at work that they do to their kid at home. We put on all sorts of masks just to get through the day, and though we may have been taught by G.I. Joe after-episode PSAs that lying was bad, we grow up understanding that sometimes being entirely truthful and open just starts fights.
So remember that your characters have their masks, as well, even someone like Brett who might assume subterfuge was some kind of sandwich. And have your “relational database,” but remember that when you tweak even a few parameters the output can change a lot.