Isobel Merille has everything. Popularity, a hot boyfriend, knowledge, money, looks.... Oh, and a tail. She hides it under a special adapted uniform. When asked, she just replies "It's called style," and flips her blonde hair over her shoulder in exasperation. The only reason she can walk is because she has electronic legs fixed onto the end of her tail. But one day, they go on a beach trip with school. She wants goes in the water, with her specially adapted swimsuit, she does. But then she stumbles across a mermaid city, and her life changes forever...