Corinne Burns is a 17-year-old girl whose mother has recently died from lung cancer. Working in a fast food restaurant to help support herself and her younger sister, Corinne is interviewed by a local television station for a story about her town’s dwindling economy amidst the Early 1980s recession. During the interview, Corinne becomes angry and belligerent towards the reporter, eventually lashing out at her overbearing and condescending boss and getting fired. The segment resonates with the station’s teenage viewers, who see Corinne as a kindred spirit. The station does a follow-up interview, which primarily consists of Corinne acting flippant and making sarcastic remarks to the journalist. However, she does manage to slip in a plug for her garage band “The Stains”, which consists of her, her sister Tracy, and their cousin Jessica.
Emboldened by appearing on television, Corinne attends a concert put on by small-time promoter Lawnboy, featuring the washed-up metal band the Metal Corpses and their opening act, an up-and-coming punk band called the Looters. Eager to end hostilities between the jaded Metal Corpses and the hedonistic Looters, Lawnboy signs the Stains without having heard them perform. Corinne and the Stains join the tour, witnessing firsthand the bands’ animosity towards one another, largely the result of the conflict between the aging Lou, the frontman for the Metal Corpses, and Billy, the Looters’ volatile lead singer.
At their first show, the Stains prove to be completely inept as a band: Neither Jessica nor Tracy can play instruments, and Corinne sings in an off-key monotone. The audience reacts angrily, prompting Corinne to lash out at them for a variety of real and perceived faults. After the show, the Metal Corpses’ guitar player Jerry is found dead in the bathroom, and the band leaves the tour. Lawnboy makes the Looters the new headliners with the Stains as their opening act. A dissatisfied Billy asks Lawnboy to replace the Stains as soon as possible.
At their next show, Corinne debuts a new, more extreme punk look, with hair dyed to resemble a skunk and a see-through blouse worn over a pair of bikini briefs. Announcing that she “never puts out,” she goes on another tirade, grabbing more media attention. While male journalists focus on Corinne’s antisocial attitude and the band’s lack of talent, female journalists understand Corinne’s rants as calls for female empowerment and hail the Stains as a new voice of feminism. Soon the Stains become a national sensation, with girls all over the country emulating Corinne in every way possible, from dyeing their hair to running away from home.
During a tour stop at a motel, Billy attempts to seduce Corinne by sharing his feelings about the band and his alleged private shame of illiteracy. Over the course of their conversation, Billy recites the lyrics to a song, “Join the Professionals” which sums up his most personal feelings about the state of the world. At their next stop, the band is met by Lawnboy’s agent, Dave Robell, with the intended replacement act for the Stains (Black Randy and the Metrosquad). Although Billy tells Corinne that he only wanted her replaced early on in the tour, Corinne lashes out at him, and at the Stains’ next show, they play a cover version of Billy’s song, which skyrockets the band to even further stardom. With Robell’s encouragement, Corinne signs a new contract, cutting Lawnboy out of any royalties and making the Stains the new headliners of the tour.
At the next show, Billy delivers a speech to the crowd about how the Stains have betrayed their “never put out” mantra by becoming corporate sell outs. When the Stains come onstage, the fans riot, and Corinne is attacked by a girl with a tube of hair dye. The tour becomes a financial disaster and Robell cancels the Stains’ contract. Corinne responds by threatening him with a bottle opener and taking the money he’s been withholding from her; Corinne then presents it to Lawnboy as an apology.
The next morning, Corinne appears on television, where a journalist chastises her for having been a poor role model to her fans. Billy apologizes for ruining Corinne’s career and asks her to come back as the Looters’ opening act. Corinne refuses; as she wanders the streets, she overhears a radio broadcast identifying the Stains’ first song as a hit record. Some time in the future, the Stains make their MTV debut, having become a successful act on Lawnboy’s new record label.