Lara is a mermaid princess who once lived in the sea, beloved by her father, the Sea King Rowan, and her six sisters. She developed a deep fascination with the human world and fell in love with a human prince, a forbidden attachment in mermaid society. Determined to be with him, she sought the help of the witch Grace and drank a potion to become human. However, Grace tricked her into consuming a different potion that caused her to dissolve into sea foam, vanishing from existence. It was said that she could only be reborn if she found true love. Two hundred years later, Lara is reborn as a human in Lake Biwa, in Shiga Prefecture, Japan, and now sets out once more to discover true love. Her primary motivation is the search for authentic love, a quest born from her past tragic experience and her lingering longing for the human world. In the present-day story, she meets Mari Otsu, a high school boxer living in Otsu City, who takes her in and provides her with a place to stay. Lara also encounters a boy named Luca, whose appearance closely resembles the prince she loved two centuries earlier. She must learn to navigate human society, adjusting to a world that is both familiar and strange. As a reborn human, it is unclear whether she retains any mermaid abilities, but her past life as a mermaid princess and her history of forbidden love shape her perspective. Her development revolves around understanding love, identity, and belonging as she interacts with the Otsu family and the people of modern Japan, gradually moving from a naive dreamer to someone capable of forming genuine human connections.