Samantha is a teen growing into womanhood, with a hopeful nature and a scientific mind. Her technical side enables her to see the world rationally and realistically, which comes in handy when you're surrounded by a mermaid, the spirit of a late grandmother, living dust bunnies and a genetic mishap that turned the family Border collie into a school guidance counsellor.

Dave and Samantha are soulmates, a fact known to everyone but themselves. Dave is dyslexic, but found that instead of it being a disability it's simply an alternate yet perfectly viable way of interfacing with the world. He uses his unique spatial talents to achieve stardom on the basketball court.

Jenny is vain, shallow and self-centered, possessing a set of personal ethics that could charitably be called "situational." She is everything that Samantha is not. Contrastingly, the two have been friends since preschool.

Remora is a 415-year-old mermaid who has decided to live on land for a while. Like all merfolk, she has the option of living 24 hours a day as half-fish, half human (i.e., Mermaid Classic), or for twelve hours fully human followed by twelve hours as a fish. In the later time frame, she lives in a tank in Samantha's room.

Samantha's father Donald works as the safety inspector at Fastrack, Inc., and her mother Jeanine has been elected state senator. Samantha has a little sister named Sophie, and three grown older siblings: Sylvester, Steve and Shondra.

When the mother of Samantha's mom passed away, she left Samantha a magic ring. When wearing it, Samantha can speak to her grandmother in any reflection. A former daredevil with a wealth of adventurous experiences, she sees her post-life duty as making sure Samantha doesn't spend her years glued to the front of a computer screen.

Roger is the mascot of the Havens High School Fighting Personal Digital Assistants. (The team used to be called the Lions until a "contribution" from a high-tech firm resulted in the name change.) Roger takes his mascot role incredibly seriously, communicating entirely through the costume's screen display.

Samantha, Dave, Jenny, Remora and Roger are joined by Thomas, Bambi, Gerald, Arnold, Lisa and Winston in the Other Clique. These are the souls who never fit into any of the school's official catalog of Cliques, so they were listed in the box marked "Other." Their own mascot is (appropriately) a cat who is the clone of a dog. They're always open to new members.