Game concept
Story
The game also links it as Stories.
From the game's encyclopedia
A Story is a personal situation tied to a Ruler.
There are many kinds of Stories — from owning a Pet Dog to becoming a Conqueror. Each is built from different elements, typically involving key Characters, Titles, or Decisions.
The game's text for patch 1.20.1.2. Words in blue are entries of the encyclopedia: hover one to read it, as in the game.
Story is an entry of Crusader Kings III's in-game encyclopedia. The game explains it: "A Story is a personal situation tied to a Ruler." The game also links it as Stories. Patch 1.20.1.2, from game/common/game_concepts/00_game_concepts.txt and game/localization/english/game_concepts_l_english.yml.
Source: game/common/game_concepts/00_game_concepts.txt, game/localization/english/game_concepts_l_english.yml and the English localisation, Crusader Kings III 1.20.1.2.