IC: Play different aspects of the same character
Inside Out is a good reference point, but it's not exactly the same - you're not just an emotion, you're a set of connected beliefs and goals. Bluebeard's Bride might be a closer point of comparison, although my game isn't quite that extreme.
Homebrew rules which I'm trying to test out here. The character's interaction with the outside world is largely freeform; the rules define who the players are, and what happens if they disagree on how the character should act.