The three are Shadoloo projects, as a lot of other animal hybrids. They all come from a series of genetic experiments with kids that are 14 years old now. The project was to try to get the perfect killer for each martial arts style, and so they were taught a style. Annie was sent for an old friend of Goro Daemon named Ataru Kayama, a Judo master, Kate was sent to Vega, to learn the Spanish Ninjitsu, Marion knows Capoeira, but that's all know about her until now, since she just arrived and doesn't remember much.

The project should have worked if it wasn't for some things:

• Sarah (who looks like some avatar of a Goddess for having so much power) caused a major short circuit (it was just her static power) at the instalation of the base she and Annie were being "studied", Annie awoke and released Sarah, the two ran away from there, beginning to search about them, and who did that with them (Sarah thinks that her power were "put" in her by Shadoloo).
• When Annie was researching about herself, she found about the project and decided that she needed to release the others and help them build a new society were the animal hybrids could live as normal people, and not as freaks as the people who saw them used to say (Sounds kinda X-men, huh?).
• Annie and Sarah made a lot of friends in the Street Fighter tournament that would help a lot, maybe you know some: Rimururu, Sakura, Ibuki, Amy Guile (Guile's daughter), Cristiane (a boxer, invented), Athena, Kensou (who becames Annie's boyfriend), Lei Kapham (Kim Kapham's sister, invented)... and they all walk together and are about 12 to 15.
• Cristiane (who discovered to be a half-angel), managed to be at the right time, at the right place, doing the right thing twice (an angel ability), and made Sarah come back to the group (she was having some dreams about killing the group -Bison's work?- and almost did so... if Cris hadn't appeared), and release Kate from a microship that was controling her to hunt the group at the same time she knocked out a guy that was taking Kate away to fix it (seriously, that was so unexpected that if it wasn't for her, Kate would be working for Shadoloo yet).
• Brian awoke (a boy that is like Sarah, but when both meet, they start remembering strange things, like that they love each other, about defeating evil from some cosmos reality and a council in a kind of heaven where they can see Lei, Amy and a third girl they don't know ready for battle... blured visions) and found Marion. When his destiny brought him near Sarah, he brought Marion to her sisters.
• Finally, Annie received a visit to join some weird guys in exchange for the cure for a insanity that arrives at female animal hybrids every month and make the the three catgirls really pissed off, ashamed, a self-hate and gives them a hard time not to do "that" with the first man around for "procreation": Shermie, Chris and Yashiro, but another three came and didn't let Annie go: Kyo, Iori and Kagura. After that, Annie decided that she would find the cure for this and to any problem that may appear from animal hybrids, since now they are a new race that will multiply and will need medical as well as social attention. Now Annie wants to be a Hybrid doctor, and is trying to pass some exams to get in a school, but she had problems with all the noise the other girls do... at least, she is happy, because she made a musical band with Athena, Brian, Kensou, Amy and Lei and now she will be -cute little girl voice- "very famous, very cool and the people will love the songs and they will like hybrids! *cute laugh*" as Annie says.