This is set in Elfhame and based on The Folk of The Air series by Holly Black. Basically you're the princess of the sea who gets sent to live with Elfhame's royal family by your mother, Queen Orlagh. Once there, you meet prince Cardan, and you know the rest since it follows the original storyline except you're y/n instead of Nicasia and Cardan actually hates Jude Duarte and only likes you. Also, yes, you're apart of the friend group with Cardan, Valerian, and Locke.