A class trip to the beach seems harmless. It should be harmless. But things go very wrong when Jisoo accidently falls into the water, and discovers she is a mermaid. Within seconds, her entire life is thrown upside down as she encounters a world completely different from the one she is used to. But things aren't so simple when she gets back home. All of a sudden, she is forced to navigate a life full of magic, friends, enemies, and betrayals. And the more she and her friends discover, the more they begin to think there's something else going on. Something much bigger than any of them. Blackpink AU