After quelling a rebellion, Drake, king of the Tidefolk, lost the only person he failed to protect—his young sister. Following the guidance of the royal relic "Heart of the Ocean", he ventured into the human world to search for his sister's whereabouts.
The missing mermaid princess had long been rescued by Ina, an orphaned girl from a poor fishing village. Ina treated the child as her own flesh and blood. To keep her from being discovered by those who profited from hunting mermaids, Ina hid the secret of her golden fish tail and guarded her at all costs.
Fate led Drake into their lives, and an unexpected bond took root from there. He was searching for his family, while she was desperately protecting hers. The cold, guarded Sea King gradually fell in love with the brave and kind human woman, unaware that the answer he had been chasing so hard had always been right beside him.
When the truth finally comes to light, will it truly make them a family, or tear apart this fragile household that has just been formed?