

Rina Toin (洞院 リナ Tōin Rina) is the mermaid princess of the North Atlantic Ocean, keeper of the green pearl and the tritagonist of the series. During school, she wears the boys' uniform instead of the girls. Initially she is depicted as beautiful but stern and bent on revenge for the capture of her best friend, Noel. Later, however, she evolves into a more mature character, and acts as an older sister figure to Lucia and Hanon. She seems to love plasma TVs and shows this love in many anime episodes. In the Pure season, she becomes close to a boxer, Masahiro. She also seems to love watching comedy shows. Her idol form is Green Pearl Voice. Some fans in the West still spell her name as Lina, because the Japanese language does not distinguish the sounds "r" and "l", treating them as the same. This means that "ri" and "li" are both represented as リ, and it can be difficult to figure out what the intended romanization is until it is established by official sources.