The film follows two friends, Joan Jett and Cherie Currie, as they rise from rebellious Southern California kids to rock stars of the now legendary group that paved the way for future generations of girl bands. Joan and Cherie fall under the Svengali-like influence of rock impresario Kim Fowley, played by Michael Shannon, who turns the group into an outrageous success and a family of misfits. With its tough-chick image and raw talent, the band quickly earns a name for itself -- and so do its two leads: Joan is the band's pure rock' n' roll heart, while Cherie, with her Bowie-Bardot looks, is the sex kitten.