Cleo, Bella, Rikki, Emma, and Charlotte are all mermaids but Charlotte can be mean at times. In season 1 and 2 Cleo, Rikki, Emma, and Charlotte are all there and Bella comes in, in season 3. Cleo became Lewis's girlfriend in season 1 and Rikki also became Zane's girlfriend in season 1. Bella and Will got together in season 3. When Cleo and Lewis think it will not work between them Lewis becomes Charlotte's boyfriend but when Lewis realizes that Charlotte is trying to hurt the girls, Lewis breaks up with her and comes back to Cleo after she runs away. The girls are trying to keep their secrets while a lot of people are trying to find out like Emma's boyfriend Ash, he said that if Emma didn't tell him then he would break up with her. Also, Will's nosy sister Sophie was poking around in Rikki's office at the mermaid statue above that Cleo and Bella made for Rikki.