Luchia Nanami (七海 るちあ, Nanami Luchia?) is the main protagonist of the anime and manga series Mermaid Melody Pichi Pichi Pitch and its second anime season, Mermaid Melody Pichi Pichi Pitch Pure. She is the Mermaid Princess of the North Pacific Ocean and the Keeper of the Pink Pearl. Lucia surfaced onto the human world to look for her pearl that she had entrusted to a boy seven years ago in order to save his life. When she succeeds, she accepts the task of uniting the seven Mermaid Princesses of the seven nations of the seas and defeating the sea monsters.
Lucia is a very cheerful person and has a very kind heart. Her idol form is Pink Pearl Voice. She has two image songs that are both from the first season of the anime (although 'Mother Symphony' from the second season is sometimes referred to as a character song of hers it is not officially considered one): Splash Dream and Koi wa Nan Darou.
Luchia means 'light' in Latin, and Nanami means 'seven seas' in Japanese. She is the only mermaid with blond hair and blue eyes.
In the anime:
Luchia Nanami ends up being the succesor to Aqua Regina. Luchia Nanami first appeared as a young mermaid seven years ago before the story started. One night when she ventured onto the sea's surface and encountered a cruise ship celebrating a festival, she met a young boy. It was love at first sight. But before anything else happened, a giant wave crashed onto the ship and the boy fell into the icy ocean. Luchia went after the boy without a second thought. She saved the boy using her precious pink mermaid pearl and the boy kept the mermaid pearl ever since.
As the story begins, Luchia surfaced on land again, but this time her purpose is to retrieve her Pink Pearl. The age 13 is considered adult age in the mermaid world, but a mermaid princess without her pearl cannot receive her full power. Heading to the human world with her pet penguin Hippo, Lucia assumed a human form and took Nanami as her surname. She works and lives in the hotel Pearl Piari, along with her "older sister" Nikora and the fortune teller Madame Taki.
In time, Lucia retrieves her pearl and also reunites with the boy who she gave it to long time ago. She also learns that there is an enemy trying to capture the seven Mermaid Princesses and obtaining their pearls for evil. They have already destroyed the Mermaids' kingdoms and captured two Princesses. Only Lucia's kingdom wasn't destroyed because Aqua Regina used her power to protect it.
While on land, Lucia meets a surfer named Kaito, who looks awfully like the boy from seven years ago. Lucia could not believe it at first, but he most certainly is the boy who had Lucia’s pearl for seven years and whom never forgot about this mermaid. Lucia and Kaito have a troubled relationship throughout the story, mainly because that the mermaid Lucia is unable to reveal her human identity to Kaito. It is said that a mermaid who willfully reveals her identity will turn into sea foam. Lucia is desperate for Kaito to learn her secret, asking him to search for her. Kaito was troubled with his feelings about the human Lucia and the mermaid Lucia, whom he thought were two different people.
Lucia has a very cheerful personality. She has a good and simple heart, and a simple mind. But she also has courage and determination in abundance. She would help anyone that is in trouble. She is also very friendly, especially when she makes “friendship rings” for Hanon as well as Rina, although she hardly knew Rina at the time. However, she is also insecure sometimes, and gets nervous whenever she sees some other pretty girls around Kaito.
Luchia shares a strong bond with her friends and fellow mermaid princesses. She met the first other mermaid princess, Hanon. Hanon and Lucia became quick friends, partly because of their similar personality. As for Rina, the green mermaid princesses, it was a hard beginning due to Rina's cold and distant exterior. However, as time passes, the three became close friends. They are always there to defeat the Dark Lovers, and they help each other whenever it is possible.
In the other arc of the story, Luchia has a rival for Kaito. And because of the upcoming danger, Kaito gave up his memory in order to protect the ones he loves. Lucia has to deal with the harsh facts that Kaito no longer remembers his precious mermaid, the enemy she has to face is very powerful, and she has to win Kaito over the girl who saved him and developed a crush on him, Michal Amagi