As the much-anticipated prom night draws near, high school senior Mandy Yang finds herself at a pivotal point in her life. With her long-time dream of gaining admission to Harvard University hanging by a thread, her well-intentioned yet frustrated school counselor, Ms. Chen, urges her to take action. Meanwhile, her loyal friend Ben Plunkett, affectionately dubbed "No Nuts" Plunkett due to a childhood peanut allergy incident, buzzes with excitement for the upcoming 80s-themed prom. In stark contrast, Mandy remains doubtful about the event, viewing it as just another high school formality—especially since it promises to be a gathering of the so-called "Everests," the elite students at the pinnacle of their social game.
When Mandy learns that her application to Harvard is stalled, she turns to Ms. Chen for advice. The counselor reminds her of the school's most popular student, Graham Lansing, whose father, Senator Lansing, is a Harvard alumnus. Sharing her intentions with Ben, Mandy devises a plan to charm Graham and leverage his connections to improve her chances at Harvard. With the support of friends Charles and Zenobia, she discovers that Graham is struggling with his psychology grades, and seizes the chance to offer her tutoring services. Although Graham initially doubts her motives, sensing a deeper intention behind her offer, he ultimately agrees to let her help.
As Mandy navigates Graham's academic hurdles, helping him master basketball techniques in exchange, their friendship blossoms. She learns about the immense pressure he faces from his father to succeed, along with his philanthropic efforts. This newfound understanding culminates in an invitation to visit Graham’s home, where she meets his mother, who assures her of a meeting with the senator at an upcoming dinner party.
Meanwhile, Ben's priorities shift as he starts neglecting his longtime bonding sessions with Mandy in favor of new experiences, particularly after crossing paths with LaToya Reynolds, the girl of his dreams. They find common ground in their passions, leading Ben to explore new horizons. As their stories unfold, a key moment arises with Ben's birthday party coinciding with Mandy's dinner invite. In a stroke of ingenuity, Mandy persuades Ben to invite LaToya, who readily agrees, resulting in a memorable night filled with unexpected connections. However, amidst the festive atmosphere, Mandy realizes she's developed deeper feelings for Graham, leading to a tender moment of connection between them.
Unfortunately, the night takes a turn when Mandy encounters Senator Lansing, prompting her to rethink her commitment to Harvard, ultimately deciding to pass on the prestigious offer after overhearing whispers about Graham's brothers planning to invite another girl while sidelining her. Overwhelmed by a sense of rejection, she runs away in tears, only to find comfort in Ben's understanding companionship.
As the narrative progresses, both Mandy and Ben embrace a fresh chapter in their lives, promising to attend prom together, igniting hope for the future. The next day at school, Mandy resolves to distance herself from Graham, while Ben makes an attempt to reconcile with an upset LaToya. Fortunately, LaToya finds it in her heart to forgive Ben on the condition they attend prom together. Back at school, Graham makes a grand gesture, revealing his genuine intentions toward Mandy. Though initially confused, she accepts his invitation.
In an unexpected twist during their revelation, Mandy learns that Ben has declined LaToya's request for a date. This leads to a volcanic confrontation and the unearthing of a compromising video that causes a rift between her and Graham. The viral chaos ensues, pushing Mandy into the role of an outcast among her peers. In a heart-wrenching moment, she confesses to Ms. Chen that she never meant to submit Graham's letter—the realization not only frees her from her Harvard aspirations but opens her heart to more fulfilling endeavors.
In a surprising yet heartwarming conclusion, Mandy reaches out to Ben, inviting him to prom as an act of goodwill. As they prepare for the evening's festivities, they lean back into their pre-prom rituals, which ultimately lead them to find comfort and closure in their rekindled friendship. As the night unfolds, Mandy and her friends arrive at the prom, only to stand out in their enthusiastic homage to 80s fashion among their peers. When the prom king and queen are announced—Ben and LaToya, boosted by Ms. Chen's influences—the moment becomes electric as Ben seizes the opportunity to declare his love for LaToya.
Encouraged by her classmates, Mandy checks her Harvard application status, stunned and overjoyed to discover her acceptance—thanks to Ms. Chen's surprise recommendation. As graduation approaches, Mandy takes the spotlight as Salutatorian, sharing an impassioned speech reflecting on her journey with Graham and the lessons she’s learned. After the ceremony, she and Ben promise to reconnect, now that he has solidified his relationship with LaToya. Mandy shares a heartfelt moment with Graham, who reveals his upcoming attendance at UT, fulfilling his father's expectations, signaling an amicable departure from their past.
Fast forward to their lives at Harvard, where Mandy's educational path unexpectedly intersects with Graham once more during a serendipitous encounter that reveals he has chosen to step away from UT to engage in inner-city non-profit work. As they reconnect, an old flame reignites, culminating in a tender kiss that signifies a new chapter in their relationship.
