There's a king, a queen, and their three kids, a 17 year old girl, her twin, a 17 year old boy, and a 15 year old girl.

You were a royal of another kingdom far, far away, but you got washed up on this kingdoms beach after your boat crashed. You want to go home, but the royal family has your magical necklace that you need to get home, but they don't know if you're a real royal or not. You'll have to prove it.