TV-Series
Description
Noel is the Mermaid Princess of the Arctic Ocean and the keeper of the Deep Blue Pearl, also known in the manga as the Indigo Pearl. She is the older twin sister of Caren, the Mermaid Princess of the Antarctic Ocean, with whom she shares a unique bond; the two were born moments apart on opposite sides of midnight. Noel has long blue hair, purple eyes, and a mole beneath the corner of one eye, marking the slight physical difference from her younger sister. She is portrayed as the calm, gentle, quiet, and intelligent type among the mermaid princesses. While she may not be as impulsive or quick to act as others, she possesses a deep sense of compassion and selflessness, and when angered she can become one of the most formidable of the princesses.

Noel's motivations are rooted in protecting her kingdom, her sister, and her fellow mermaid princesses. Her role in the story begins tragically when her kingdom is attacked by the antagonist Gaito. In an act of self-sacrifice, she allows herself to be captured so that her fellow princess Rina can escape, spending much of the first season imprisoned and asleep within Gaito's castle. She is eventually rescued by Lucia, Hanon, Rina, and Caren near the end of the first season, and she rejoins her sister after a long separation. This sacrifice and subsequent rescue form the core of her early narrative arc.

After being freed, Noel assists in the fight against Gaito and later returns to help rebuild her kingdom. She reappears in the human world alongside Caren and Coco, providing comic relief but also serving a more active supporting role. In the second season, Pure, Noel becomes more involved in the plot against Michel. She often acts as a voice of reason among the second trio of princesses, and in one episode she even puts on glasses and assists in theorizing about the nature of Miracle Bay. While not one to make decisions without thought, Noel is fully willing to sacrifice herself again if it means saving her friends and allies.

Key relationships include her twin sister Caren, with whom she shares a deep but occasionally strained bond due to their long separation; she is also close to Rina, as the two searched for other mermaid princesses together before Noel's capture. Within the larger group of mermaid princesses, Noel maintains supportive bonds with Lucia, Hanon, and the others. Her relationship with Caren is notably tested when Caren misinterprets the circumstances of Noel's capture, believing Rina to have betrayed her, but they are ultimately reconciled.

Throughout the series, Noel's development involves moving from a victim who was captured and isolated to an active participant in the final battles. She is also part of comedic subplots in the human world, where she and Caren are sometimes depicted flirting with human boys to make Hanon and Rina jealous. She possesses three forms: her natural mermaid form, her human form, and her singer form, Deep Blue Pearl Voice. Her magic is tied to her voice and her pearl, which she uses to perform musical attacks alongside the other mermaid princesses.