Jen and Mel operate The Breaker Upperers, an unconventional agency based in Auckland dedicated to aiding individuals in breaking up with their partners. Their methods often defy norms, such as when they impersonate police officers to inform a woman named Anna that her husband's corpse is missing—while he is actually hiding in their car.
Having been friends since their twenties due to a shared romantic interest in Joe, who has since returned to town with his family, Mel has moved on while Jen remains fixated on him. Meanwhile, Mel finds herself attracted to a teenage client, Jordan, who is too intimidated to end his relationship with his fierce girlfriend, Sepa. This budding romance causes quite a stir, especially after a confrontation with Sepa and her crew leads to a slap across Jen's face. Not long after, Mel and Jordan begin dating.
Their complex lives take another turn when they encounter Anna once more. Still under the impression that they are law enforcement, Anna seeks their help, and the bond between her and Mel grows, leaving Jen feeling neglected. Eager for answers, Anna presses them for information regarding her husband’s case.
In a comical yet precarious situation, Jen and Mel don police attire and infiltrate a local precinct, only to be mistaken for strippers by an officer. The ensuing embarrassment leads a furious Anna to exit their lives, branding their enterprise as morally questionable. The weight of Anna's reprimand resonates with Mel, prompting her to think about leaving the agency, which infuriates Jen. Bitter memories resurface as Jen reminds Mel of her previous fallout with Joe, blaming her for their split.
Later, during a meaningful dinner, Jen expresses her enduring feelings for Joe, only to be met with ridicule and the acknowledgment of his past infidelities. He insists that while he was a wayward partner before, he's now matured.
Meanwhile, Mel continues her involvement with Jordan. Though he shows genuine affection, she questions his maturity and recognizes he still harbors feelings for Sepa, who has been a pillar of support in his rugby aspirations. A chance encounter at a shop reveals Mel is pregnant, complicating her feelings about Jordan and their future together.
Determined to play matchmaker, Jen seeks out Sepa’s help. At the local pub, as Jordan celebrates securing a rugby contract with the Gold Coast Titans, Mel begins to worry when he suggests giving up the opportunity to stay by her side during her pregnancy. However, Sepa steps in, expressing her reformed feelings for Jordan before serenading him along with her posse. In a powerful moment of friendship, Jen dedicates a song to Mel.
Ultimately, Mel encourages Jordan to recommit to his rugby career while promising to support one another, leading to a heartfelt reconciliation with Sepa. As the dust settles, Jen and Mel mend their friendship, transforming their agency to assist clients with both break-ups and make-ups. The film closes on a hopeful note, revealing Anna and Mel have reconciled, while Jordan thrives in the Gold Coast, cherishing moments with his infant daughter.
