Single mother Jean constantly relocates every time she endures heartbreak from yet another failed relationship, leaving her teenage daughter, Holly, feeling frustrated. The story begins with Holly excitedly preparing for her first school dance, which is just a week away. However, chaos ensues when Jean's current boyfriend shows up and confesses his infidelity, prompting Jean to retaliate by throwing a cake in his face.
Following this latest emotional setback, Jean, Holly, and her younger sister, Zoe, move to Brooklyn. Here, Holly befriends a girl named Amy and hatches an inventive scheme to create a fictitious admirer for her mother, hoping it will lift Jean’s spirits and stop the constant moves. Holly overhears her friend Amy's uncle, Ben, ordering flowers and decides to seek his advice under the pretext of needing help with an English paper on romantic leads and their modern equivalents.
With newfound knowledge, Holly begins sending her mother a series of gifts and love notes from this imaginary admirer, whom she chooses to name Ben. As Jean becomes captivated by this mysterious suitor, Holly struggles to maintain the ruse while also developing feelings for a charming boy in her class, Adam, played by Ben Feldman. Her past experiences of constantly moving have made Holly hesitant to get too close to anyone.
As the charade unfolds, Holly begins to see Ben's true qualities, leading her to believe he is indeed the ideal man for her mother. However, the dilemma arises when she realizes her mother cannot interact with the real Ben without exposing Holly's deception. In a twist, Holly convinces Adam to pose as Ben during a phone call to break things off with Jean, but Adam unintentionally reveals his own feelings for Holly instead.
The following day, Adam confesses his affection for Holly with a kiss. Meanwhile, Lenny, played by Mike O'Malley, who is enamored with Jean, proposes a possible relationship, prompting Holly to take drastic actions. She enlists Adam's help once more, this time disguising herself as Ben's secretary to facilitate a meeting between her mother and the real Ben.
In a comedic and chaotic sequence, Holly mistakenly believes that Ben is about to marry someone else and disrupts the wedding, only to discover that Ben was there catering for a friend. After a heated confrontation with Ben, Holly eventually confesses the entire scheme to Jean, leading to tension between them.
As days go by, their relationship remains strained, highlighted by a misunderstanding involving one of Adam's drawings of "Princess Holly." In a desperate plea, Holly requests to move again, but Jean, feeling humiliated, wishes to stay put. Eventually, facing her daughter's heartfelt request, Jean agrees to consider relocation once more. However, just as Adam is about to leave Holly, he gives her mother his drawing, which conveys a deeper message about support and commitment.
This act touches Jean deeply, prompting her to connect with Holly's online persona and re-evaluate her own choices. A conversation with Adam, who mistakenly thinks he's talking to Holly, encourages Jean to confront her shortcomings and remain with her family. Soon, she apologizes to Holly and invites her to see the drawing’s reverse side, sparking joy in her daughter’s heart.
Ultimately, intrigued by what Holly shared, Ben and Jean finally come face-to-face, allowing Jean to find her "perfect match." With a newfound stability in their lives, Holly can express her feelings for Adam. The climax of the film culminates at the school dance, where Holly and Adam finally attend together, marking a hopeful beginning for their relationship.
