Fly: Goose Girl Retold

Two princesses. One prince. And the war has just begun.
Once upon a time...
Princess Ava was sent to a neighbouring kingdom as a lady-in-waiting to her sister, their future queen. Until a runaway horse, a case of amnesia and a cold-hearted king conspire to bring her to the prince's attention.
Now the prince believes Ava is his bride, and her sister is just a serving maid. One thing is certain: the prince must marry one of the princesses, or there will be war.
But when all's fair in love and war...who will win the battle for the prince's heart?