Characters are the citizens you can befriend who can live in the Valley.
Commonly after encountering a character the player will need to complete a series of quests, then place and purchase their house, before they move into the Valley.
Characters in the game display in the Characters tab of the Collection menu, grouped by the area they're encountered, and then by Universe. Villagers that have moved to the Valley can be selected to view their Role, current Friendship level and progress, and Favorite Things of the Day. Prior to moving to the Valley, the Character will display in the Collection tab, but their image will be desaturated and when selected a "Be a friend!" overlay will display over their image.