Sunny is a princess of the South Pacific Ocean, and Courtney's older sister, despite being a yellow mermaid. She came to land to help her sister defeat Jiko and Christina.
Sunny's personality depends on the time of day. In the morning, she is calm and mostly hungry; in the afternoon, she is wild and bound to crash into something, and in the evenings, she is sleepy and bound to fall asleep at certain times.
In her mermaid form, her hair, bra, eyes and tail are all yellow.
Sunny has a smooth voice, with an English accent. However, she has a loud voice when she sings.
These are the songs she sings:
- You Belong With Me (by Taylor Swift)
- Black Diamond (English version; by Nana Mizuki; duet with Katie)
- So Close (by Jennette McCurdy; trio with Courtney and Iris)
- The Climb (by Miley Cyrus; with Mary Anne, Bianca and Isabella)
- No Thank You (English version; by Hatsune Miku; duet with Stacy)
Voice Actor (Japanese): Ema Kogure
Voice Actor (English): Monica Rial