The series is not set in the main comics continuity, and is intended for children. It features a younger version of Supergirl than most other versions.
In the series, Argo is the name of a moon of Krypton, not a city, and was not destroyed. Instead, Kara hid inside her father's rocket, thinking he would find her inside and release her, but instead found herself sent to Earth.
- Kara Zor-El/Supergirl, the main character.
- Zor-El, Kara's father, accidentally sent her in a rocket to earth, to meet Superman.
- Alura, Kara's mother.
- Superman, Kara's famous cousin.
- Lena Luthor, a young scientist Kara meets at school.
- Belinda Zee, a Bizarro version of Supergirl.