Switched With My Stepsister: Bodyswap, Gender Change

Natalie and Ben are new step-siblings and they're not at all thrilled about it. They like their parents well enough, it's each other they can't stand. Since both of them are college students who rarely have to see one another it's not much of a problem, but when they go on a family vacation to Rome tempers flare.

After they stumble upon a secret chamber amidst some old ruins their lives take a turn for the strange. A long dormant ancient power causes them to switch bodies! They'll have to work together to figure out how to switch back and in the process they'll become closer than they ever thought possible. They might even have a little fun along the way.