In the vibrant atmosphere of the 1990s, 16-year-old Johanna Morrigan makes her home on a council estate in Wolverhampton. Here, she lives with her ambitious rock star father, Pat, her weary mother Angie, her brothers Krissi and Lupin, along with two lively infant twins. Johanna harbors a deep desire to escape her mundane life and become a writer. She finds solace in conversing with the portraits of her heroes that adorn her bedroom walls.
When a poem she penned is chosen for a televised competition, she struggles with anxiety and ends up embarrassing herself in front of the nation. To add to her woes, an offhand comment leads to her family's illegal breeding of Border Collies being exposed, resulting in her father losing his disability benefits. Determined to support her family, Johanna explores opportunities to generate income.
With a nudge from Krissi, she discovers D&ME, a London-based music magazine in need of a rock critic. Eagerly, she submits a review of the Annie soundtrack. However, when she arrives for an interview, she learns that the staff had assumed her submission was a joke. Nevertheless, her passion shines through as she persuades them to give her a chance, and she’s assigned to cover a live performance by the Manic Street Preachers in Birmingham.
In her quest for reinvention, Johanna adopts a striking look with bright red hair and the pseudonym "Dolly Wilde." She attends her first rock concert and becomes captivated by the music scene. D&ME further supports her passion by sending her to Dublin to interview the captivating musician John Kite, who quickly falls for her vibrant charm. Their day together is filled with laughter and connection as Johanna steps onto the stage beside him, forging a bond she cherishes deeply.
Upon returning home, Johanna writes a raving article on John, but her editor dismisses it as trivial, calling it the work of a lovesick teenager. Realizing that harsh criticism might lead to her desired success, she adopts a new approach, penning biting reviews as Dolly. Now a recognizable and ruthless critic, she is finally able to contribute financially to her family, while navigating her newfound sexuality, much to Krissi's dismay.
In a bid for fame, Pat tasks Johanna with promoting his band's single, only for it to be met with scorn at a D&ME gathering, leading to a humiliating incident involving the record. At an industry event, Johanna is awarded the title of "Arsehole of the Year," which brings her face-to-face with John. In a drunken moment, she confesses her feelings and tries to kiss him, but he gently rebuffs her.
The following day, Johanna writes an article detailing John’s personal life, jeopardizing the trust they built. Quitting school leads to confrontations with her family, who demand she reconsider her rebellious path; Johanna coldly reminds them that her income supports them. At a party with her colleagues, she is taken aback by their backhanded remarks about her, prompting an impassioned outburst that results in her quitting.
Lost and desolate, Johanna attempts to find solace in drinking, leading to a harrowing event where she inflicts harm upon herself. Unconscious from a mix of drinks and accidents, she wakes in the hospital, mending her relationship with her family. Seeking redemption, she actively tries to apologize to all the musicians she unjustly criticized.
Her journey of self-discovery continues as she writes an introspective article on self-harm, catching the attention of The Face magazine, where she's invited to write her own column titled "Building a Girl."
When Johanna manages to find John again, she sincerely apologizes for her earlier article and presents him with her original writing about him as a peace offering, along with a lock of her freshly cut hair. John graciously forgives her, expressing that while romance might not be in the cards for now, he values their friendship. In a moment of reflection and breaking the fourth wall, Johanna reminds her audience that a girl always has the capacity to reinvent herself for the better.
