Kim Sertori

Kim Sertori is Cleo's younger sister. Her role is the series is a minor villain one, intended to serve as a source of constant conflict and friction, in both the girls' home life and their mermaid life. She is incredibly nosy and likes to snoop on her sister. Her favorite pastime seems to be vexing Cleo and she always is coming up with new schemes. In addition, Kim is also bossy, manipulative, and extremely selfish, only looking out for herself and not caring who she has to hurt or manipulate to get what she wants. She is also shown to delight in seeing Cleo humiliated or wronged and manipulates her easily and frequently. This is not limited to just Cleo however, as she has shown the same delight in seeing Sophie fire someone unfairly, suggesting she admires other people who are corrupt like she often is. Occasionally, Kim displays a softer more sensitive side. She is shown to be greatly saddened by hers and Cleo's mother leaving expressing feelings of loneliness.