Lucy, a former actress turned accomplished matchmaker at the New York City firm Adore, has successfully orchestrated nine marriages, despite her own voluntary celibacy. She holds a firm belief that her future partner must be wealthy. At a wedding for one of her successful matches, she crosses paths with Harry Castillo, played by Pedro Pascal, the wealthy brother of the groom. While Harry is eager to ask Lucy out, she quickly deflects his advances, suggesting he should become a client at Adore instead. Fate brings her back together with her ex-boyfriend, John, portrayed by Chris Evans, who is now a caterer at the event. Their meeting leads to a nostalgic conversation, revealing that John is still pursuing his dream of acting.
As Harry persists in his pursuit of Lucy, he charms her with culinary dates in upscale locations. Lucy, viewing Harry as a "unicorn" because of his rugged good looks and fortune, expresses her insecurities, wondering what he finds appealing in her. Harry reassures her, citing his admiration for her unique perspective on life and admitting that his extravagant gestures make her feel cherished. Over time, they embark on an official romance, which inadvertently affects Lucy’s matchmaking capabilities, leading her to pair a client named Sophie with another client, Mark.
However, complications arise when it is revealed that Mark has assaulted Sophie during their relationship, leaving Lucy questioning her skills as a matchmaker. Her boss, Marin Ireland, who plays Violet, provides her with time off to recuperate from the emotionally taxing situation. Ignoring Violet’s advice, Lucy reaches out to Sophie to express her remorse, but Sophie accuses her of rushing to make matches without ensuring their safety, leading to a painful severing of ties.
In search of a fresh start, Lucy decides to sublet her apartment for a short trip to Iceland with Harry but soon realizes their relationship lacks genuine romantic feelings, prompting her to end things amicably. With no place to call home, she temporarily moves in with John, and they escape the city to get some peace in an upstate retreat. At a wedding catered by John's company, Lucy finds herself kissing him during a dance, igniting feelings of confusion within John, who questions whether they should rekindle their past relationship despite his financial challenges.
The plot thickens as Lucy receives a distressing call from Sophie, who is in a precarious situation with Mark attempting to enter her apartment. Lucy bravely instructs Sophie to stand her ground while John drives her to the rescue. Although Mark has fled by the time they arrive, Lucy reassures Sophie that she will eventually discover true love. Just before he departs, John makes a heartfelt declaration to Lucy, promising to love her unconditionally, which she reciprocates.
Time passes, and Lucy is unexpectedly offered Violet's position as head of Adore’s New York branch while Violet plans to move elsewhere. Despite her current role, Lucy contemplates leaving the company. In a romantic turn of events, during a picnic in Central Park, John proposes, and Lucy joyfully accepts with a kiss.
As the credits roll, the film captures various couples at the City Clerk’s office as they joyfully apply for and receive their marriage licenses, hinting at the enduring power of love and connection.
