The Idea Factory - Heir of the Island
On an island off the coast of some country, there is a secluded community of "monsters" under self-exile to avoid causing harm to others. One of the houses is inherited by someone from the mainland, and instead of just selling the place like the community requested, they move there. The daughter inherited the "monster" genes from her father, who died soon before his parents did (the ones they inherited the house from). The daughter and the mother are oblivious to all of these facts when they move there.