Luchia (or Lucia), is the Mermaid Princess of the North Pacific Ocean, keeper of the pink pearl, and the main character of the story. She goes up to land to search for a boy she saved seven years ago. She is unaware of the danger in the marine world and of her real mission until she is told of them by her "older sister", Nikora. She is characterized by her simplicity and naïveté, but with having a strong will, typical traits of shōjo manga heroines. Her idol form is Pink Pearl Voice. Of all the mermaids in the series, Lucia's mermaid form and human form contrast the most (Luchia has dark blonde hair and brown eyes in the surface while having lighter blonde hair and light blue eyes while at sea).