An unusual girl, Mila Nakano, lives in a town on the Australian Coral Coast. She has the rare ability to see sounds and hear colors. Mila works as a caretaker at a nature reserve, knows the underwater reef and lagoon like the back of her hand and is ready to do anything to protect her world. Even to forget the irresistible millionaire Richard Grundy. He appears under the guise of a tourist, and Mila shows him the beauty of the coast and reveals the secrets of the underwater kingdom. Having learned that he is going to turn the coastline into a fashionable resort and thereby cause irreparable damage to nature, Mila cannot stand such betrayal and tries to throw Rich out of her life. And Rich, although fascinated by the lovely mermaid, is also not ready to sacrifice business interests for her...