Really just a remake of Beauty and the Beast, set in modern day Italy. Arabella (my character) was an heiress given everything her heart desired by her wealthy merchant father, and after his passing came to own his Manor and vineyards. As a joke, some fae turned her hands into cat paws and she was so furious she destroyed their home, a sacred ring of old trees in the middle of the nearby forest. The leader of the fae turned her entire self into the full beast appearance of a feral white cat. There is no defined end to the curse, because as the Fae King put it, "The curse will end when your lesson is finished." That was seventeen years ago. She has actually become a blight on the nearby city, because she stalks and kills people when they're alone. She'll destroy cattle and other livestock, and kidnaps children (mostly young girls) to keep them as her servants. If the girls are under her roof long enough, the curse affects them as well and they're changed into animals and won't be freed until she is.
Your character would stumble upon her home either because of a storm, or maybe he's on a hiking trip. Whatever reason you would like to use keeps him there. It's pretty much just the story of Beauty and the Beast.