Arianna is a very shy little fairy princess who always wears her wetsuit, goggles, gloves, swim cap, nose-plugs, swim-socks, water-shoes, flippers, snorkel, scuba regulator, tiara, tutu, fairy wings and fairy mask that covers her entire face all the time. She attends an underwater boarding school for fairy princesses. She attends the first grade and she has 25 other fairy princesses in her class, of which 13 she shares her dorm room with.