Issa is your average teenage girl. She goes to high school, chuckles about silly jokes, swoons about boys, has average grades, likes music, movies and games, is even a bit nerdy if you like to call it that. Oh, and she is a shape shifter. There's also that.
A few years ago her father disappeared under mysterious circumstances. Presumed dead, he gave custody over his daughter to the only man he ever trusted, Professor Ulysses Fonzeheart. Who in their right mind names their son Ulysses? What kind of name is this, anyway? And Fonzeheart? Really?
Anyways, Issa, who is actually named Melissa but you know how kids are with their nicknames and besties 'n stuff, she lives with the Professor who she fondly calls Doctor (she might or might not have asked him for a Sonic Screwdriver) and spends her time doing things teenage girls do. And investigate the disappearance of her father. She does that too. Which means she obviously gets into dangerous territory, not realizing that her father disappeared for a reason - to protect her from some very shady guys who are not very happy with her investigating and all.
But who cares about that anyway when you're busy looking at adorable kittens online?