The moon and sun kingdoms are exact opposites as you would expect one with the powers of water and the other fire, bestowed by the goddess of your kingdom.
And as you could expect they fought quite frequently.
Ariel is a princess of the moon kingdom, with her mother pushing her into a life she doesn’t want.
Amber is a spy from the sun kingdom who was tasked with bringing a certain princess home due to Ariel being the heir.
But Ariel hides a secret that might not take well to many people considering her to be a princess.