yuck, this is charlotte, the evil one!
Charlotte is the new girl in town and is the girls' rival during series two. She enjoys various forms of art, appreciates the sciences and 'becomes' Lewis's controlling girlfriend after Cleo leaves him. She hates Cleo as well as Rikki and Emma, who hate her back, a dislike made even stronger after she becomes the fourth mermaid late in series two, armed with the powers of all three girls. Charlotte is eventually revealed to be the granddaughter of Gracie, one of the original three mermaids who 50 years earlier gave her powers up to the 50 year full moon. In the end of the second season, she becomes increasingly jealous of Cleo and asks Lewis to stop talking to the other girls. She then knocks Cleo down and takes Gracie's locket, which the girls had found in the early part of season one, hiding Lewis' cell phone when Cleo tries to call him. Charlotte then gives Lewis an ultimatum, Cleo or her, and Lewis says that there is no choice, he of course picks Cleo. Charlotte then tries to get revenge by planning to force Emma, Rikki and Cleo into the moon pool during the full planetary alignment, which would strip them of their mermaid powers and abilities, so that Lewis would only care for her. In the end, she is the one who loses everything.
this is lewis!
Lewis has been Cleo's friend since they were five, and following the girls' transformation, he also becomes friends with Rikki and Emma. He is academically gifted, thinks of himself as a scientist and has a passion for fishing. He discovers the girls' secret early on in the series and becomes determined to find the cause. He is in love with Cleo, who reciprocates the feeling and the two form a relationship late in series one. After first full moon of series two, Cleo breaks up with Lewis. They stay friends but remain a little embarrassed. Lewis develops a friendship with Charlotte, the new girl, who has a crush on Lewis and becomes his controlling girlfriend. At the end of series two, Lewis dumps Charlotte because of her behaviour towards the other girls, mostly Cleo. After he saves Cleo from a shark reef, they get back together.
ugh this is zane!
Zane is the local bad boy, and seems to think that he can get away with anything because his dad is rich. He appears to be arrogant, but has been seen to have a softer side. He desperately wants to impress his father, local land developer Harrison Bennett, who is more arrogant. Zane is an excellent swimmer. After becoming trapped on a sinking boat, he is rescued by Emma, and sees the end of her tail before she is able to slip away. Because of this, Zane becomes obsessed with finding the "sea monster". Later on in the first season, to the disappointment of Miriam who assumed that she was with Zane, Rikki and Zane develop feelings for each other after being locked out on a penthouse balcony in a hotel that Harrison Bennett is giving an advertising speech at. While they later break up at the end of the first season because they are "too different" from each other, they rekindle their relationship in the second season after Zane discovers the girls are still mermaids
Ash is the current supervisor of the Juicenet Cafe (to Emma's disappointment at first, since she wanted the job). Ash is a keen horse rider and has worked as a riding coach. He and Emma have formed a relationship and have gone out on a few dates. In the middle of the second season, in the episode 'Moonstruck', Emma was affected by the full moon (with Cleo and Rikki) and almost revealed her secret by calling him into the bathroom when she was wet with a tail. Luckily, Lewis steps in and stops him. During the season two finale, Emma reveals that she is a mermaid to Ash, and he only has time to smile and say, "Cool" before the end credits roll. Ash also has a falling out with Zane in the Juicenet Cafe, causing the girl's group to split for an episode.