While Paper Mario: The Origami King doesn’t have a traditional experience points system, instead getting coins and confetti after a battle, this may not have always been intended to be the case.
A datamine of the game’s save file has revealed some interesting information, with one of the variables included being “battle_win_exP”. This is in the final game and you can see it in a file like Notepad.
It is not known when this was scrapped and how it would have been used, but it would have been interesting to see.