Your neighbour has jointed a "student exchange program" with the elf tribe. A young elf girl is living in your town to learn about human's culture. In exchange, your neighbour's gramps stays in the elf's region as a "student "...
All of my sims have their own outfits, skills, careers, likes and dislikes, additional traits, lifestyles… etc. (Sometimes not 😅) Go into the game and check it out for yourself!