In 2007, Holly Berenson, played by Katherine Heigl, runs a quaint bakery in Atlanta, while Eric Messer, known as Messer, interpreted by Josh Duhamel, is a budding television technical sports director for the Atlanta Hawks. Their friends, Peter and Alison, attempt to set them up on a blind date that goes spectacularly wrong, leaving both of them with a strong dislike for each other. The evening is a disaster from the start: Eric arrives an hour late, pedaling over on his bike while Holly is dressed elegantly for the occasion. In a moment of frustration, Holly ends up driving herself, only to find that Eric never made any reservations. As the night unfolds, she discovers that Eric had planned to meet someone else after dinner, deepening their mutual resentment.
As the years pass, Peter and Alison marry and welcome a daughter, Sophie Christina Novak. They choose Holly and Eric to be Sophie’s godparents, which forces the pair to temporarily tolerate each other for the sake of the child. The discord between them is evident during a lavish birthday celebration for Sophie, where their interactions are fraught with tension.
Tragedy strikes when Peter and Alison die in a car accident, leaving behind a will that names Holly and Eric as joint guardians for Sophie. With the little girl now under the care of Child Protective Services (CPS), they quickly realize they must convince the agency that they can provide a suitable home. The couple is left in a financial bind, as Peter and Alison's house is their only asset, lacking funds to support Sophie’s needs.
Reluctantly, Holly and Messer move into Sophie’s home to take care of her, but their cohabitation presents numerous challenges. Eric expresses his concern over the financial aspects, noting that Peter was a junior partner at a law firm, and he lacks sufficient resources. Despite their complications, Holly remains determined to honor Peter and Alison’s choices.
As the neighbors rally around to share their parental wisdom, Holly learns to lean on Eric. However, a pivotal moment arrives when Holly has to leave Sophie with Messer while she manages an important catering job. That same night, he is offered a chance to direct a significant basketball game, leading to chaos when Sophie’s cries distract him.
In a positive turn of events, Holly meets Sam, Sophie’s pediatrician, and they develop an attraction. But when Messer witnesses Holly kiss Sam, complications arise. The pressures of parenting mount, leading Holly to abandon plans for her business expansion as expenses spiral. Eventually, Eric proposes investing in Holly's company, strengthening their bond and adding layers to their relationship.
> “You must make a firm commitment either to stay together, or break up,” warns their caseworker, Janine.
As their feelings deepen, things take a turn when Eric considers a job opportunity in Phoenix, a move he fails to discuss with Holly. The ensuing tension culminates in a confrontation, revealing Holly's heartbreak over what feels like Eric's abandonment. When Thanksgiving arrives, Holly is seen with Sam, igniting further conflict between her and Eric.
However, an emotional moment unfolds when Sophie calls Holly "Mama" for the first time, stirring unshakable feelings in both them. Following a day that culminates in an important meeting with Janine, Holly realizes that she needs Eric and loves him dearly. In a frantic dash, she heads for the airport to catch him before he departs. Alas, when they miss each other, she returns home disheartened only to find Eric there, having realized the truth.
The film draws to a heartwarming conclusion with a celebration of Sophie's second birthday. Surrounded by supportive neighbors and friends, Holly prepares an extravagant cupcake display and a cake symbolizing their shared journey. With a heartfelt kiss, they commit to each other, as guests joyfully sing 'Happy Birthday' to Sophie, encapsulating the essence of family and love that has formed amidst adversity.
