Vampires, Mermaids, Werewolves, Changelings, Trolls, etc. are all real. They live within the world and humans are aware of their existence. There's accommodations made for those that need them, vampires work during the night and they get blood from grocery stores; mermaids have underwater cities and laws that require humans to be mindful of what ends up in the waters; and werewolves have shelters to go to during the full moon to run free and not harm someone.
Some things we could do inside this world:
- Camp for Supernatural kids, we play a couple of adults that own and operate it
- Workers at a cafe/bar/club struggling to survive
- Childhood friends reuniting after getting separated
- Park Rangers in charge of keeping those within their forests safe
- Suggest something of your own!