Joan Hearts Kristen, Cherie's Way Into Dakota

Stars of The Runaways, Kristen Stewart and Dakota Fanning, win over their real-life characters, Joan Jett and Cherie Currie

Our early fab word on The Runaways is in, but is the news just as good regarding how Joan Jett and Cherie Currie feel about Kristen Stewart and Dakota Fanning playing them?

Kristen, super comfortable in a yellow tank and plaid cuffed button-up top, told us at yesterday's junket how nervous she was to first meet Jett:

"I met Joan after I got the part, and it was so scary because it sort of felt like this was the meeting that either fires me or keeps me on," Stewart said, smiling as she recalled the encounter.

"My hair was still long, I was about to do New Moon. I sort of felt like [Joan] was going to look at me and go like, 'What makes you think you can be me?'"

Little did K.Stew know her hair is what made her cool with Joan—after a seemingly unsure start:

Rock 'n' roll legend Jett revealed exactly what sealed the deal to keep Stewart on board:

"I asked [Kristen], 'Are you going to cut your hair?' And when she said yes, it really gave me a sense of comfort that she was very committed to becoming me. Then I burned her a bunch of CDs, all the studio records, bootlegs...so she could hear the onstage banter, hear the audience yelling...It was for her to get a sense of who I was, and who was this person was she was used to seeing pictures of, of black hair, heavy makeup and a guitar. [Kristen] got that."

The adoration was mucho mutual when Cherie Currie first met Dakota Fanning. C.C. filled us in on those deets:

"We met for lunch. [Dakota] actually came to The Roxy where I just did Cherry Bomb for a benefit. She actually came sick to see that. She was really cute because she goes, 'I watched you up there and I realized I have my work cut out for me.' I thought, 'Thank you, Dakota!'"

But how Fanning got her hands on the script is too weird, as Cherie Curry revealed to us:

"When we went to lunch I said, 'How did you get involved with this film?' And [Dakota] says, 'You're not going to believe this, but I went to school and one of my girlfriends had these temporary tattoos and I picked out a single cherry and put it on my shoulder. When I got home and showed my mom, my mom was holding a script and goes you're not going to believe this, but you're supposed to play a girl who has a cherry tattoo.'

"Dakota just thought that was a sign," continued Currie, amazed all over again telling the kismet tale. "Then she read the script and she said there was absolutely no one else on the planet that could play this role. I said, 'Why do you say that?' and she said, 'What are they gonna do, get a 26-year-old to play a 15-year-old?' I thought, how wise beyond her years [Dakota] is."

Yep, Kristen, too. Don't believe us? Watch the damn flick.