Rina Touin  

Green Pearl Mermaid Princess, 洞院 リナ

Rina is a Mermaid Princess from the North Atlantic Ocean who possesses the Green Pearl. She's part of the main trio with Lucia and Hanon, appearing throughout the series. Initially, she's depicted as stern and focused on revenge for her friend Noel's capture. However, she later evolves into a more mature character and acts as an older sister figure to Lucia and Hanon. Rina loves plasma TVs and often shows this in anime episodes. She also enjoys watching comedy shows. During the attack on their kingdom by Gaito, Rina escaped with Noel and was later seeking the other Mermaids. When they encountered Gaito and Yuuri, their intent was to harm both of them. However, Noel took the attacks to protect Rina. Following this event, Rina traveled to the human world in search of revenge against Gaito for Noel's death. She later transferred to the same school as Lucia and Hanon, wearing the male school uniform. Initially, she was hostile towards Kaito due to his resemblance to Gaito, but this changed when she learned the truth about him. Now, Rina is friends with Lucia, Hanon, and Kaito.