The mermaid princess Anna sacrificed her legs using forbidden magic to save CEO Kyle from drowning, allowing him to stand again. However, Kyle mistakenly credited his gratitude to his childhood friend Maria, treating Anna with indifference and, believing slanderous words, expelled her from the house. Anna was rescued by her own kind, and after regaining her legs, she vowed revenge. When she returned astonishingly as the daughter of the sea god, publicly revealing the truth and reclaiming her legs, Kyle was filled with regret. But this time, the mermaid princess would no longer be soft-hearted; she intended to make everyone who wronged her pay the price.