Archie Arnold has harbored feelings for his best friend, Amelia Brown, since their early childhood, yet he has always struggled to summon the courage necessary to express his love. As their final term at Heathbrook Academy begins, Archie is determined to finally confess his feelings to Amelia. However, his plans go awry with the arrival of the charismatic American transfer student, Billy Walsh. The moment he steps foot on campus, Billy becomes the center of attention, capturing the hearts of his classmates, including Amelia, while leaving Archie feeling increasingly invisible.
Billy's infectious charm and impressive talents quickly propel him to stardom at the academy. He excels academically, earns accolades as the captain of both the swim and rugby teams, and has the entire student body, except for Archie, captivated by his presence. This newfound admiration stirs a deep jealousy within Archie, especially as he watches Amelia effortlessly fall for Billy.
Adding to the dynamics, Archie's parents, Lilly and George, maintain a close friendship with Rupert, Amelia's father. During an intimate family gathering, they encourage Rupert, who is still mourning his late wife Jules, to embrace love again. Lilly and George share their own journey of rekindled affection, crediting a mysterious "Love Doctor" who helped them restore their marital bliss. When Amelia catches wind of this conversation, she presses Archie to acquire the phone number of this Love Doctor, convinced that this individual can assist her in navigating her feelings for Billy.
Initially, driven by jealousy, Archie refuses to help, leading to a heated argument and leaving Amelia feeling hurt. In a gesture of reconciliation, he eventually decides to retrieve the contact number from his parents. However, in a twist of fate, he takes it upon himself to pose as the Love Doctor, employing a second mobile phone and a face-altering app to maintain his ruse.
In the midst of this turmoil, Amelia gets swept up in peer pressure after overhearing some unflattering gossip from the popular girl Amber in the school bathroom. This prompts her to reinvent her image, opting for revealing outfits and trendy hairstyles in an attempt to grab Billy's attention. Unfortunately, under Archie's dubious guidance as the Love Doctor, her efforts backfire spectacularly. Following a disastrous date characterized by awkwardness and miscommunication, Billy loses interest in Amelia.
Heartbroken and desperate for redemption, Amelia takes to the school intercom for a heartfelt public apology. Despite her efforts, she finds herself entering into a relationship with Billy, leaving Archie to confront the painful reality of his one-sided affection. Resolved to distance himself from Amelia, he braces himself for graduation.
As the commencement festivities unfold, Amelia starts to reflect on her bond with Archie, ultimately acknowledging her deep-rooted feelings for him. On the night of Heathbrook's June Ball, instead of attending with Billy, she sneaks away to confess her love to Archie. Elated by her arrival, Archie eagerly accepts her invitation to the ball. However, as they prepare for the night, Amelia's text to the Love Doctor—who is effectively Archie—triggers a moment of realization. Hurt and betrayed, she confronts Archie, leading her to abandon their plans and head to the ball alone.
Meanwhile, Billy and Amelia come to terms with their relationship, opting to transition to a friendship instead. In a moment of clarity, Archie races after Amelia, but he faces a humiliating setback courtesy of the swim team, who take offense and give him a rough time. It is Billy who ultimately comes to Archie's aid, encouraging him to pursue Amelia.
In a climactic showdown, Archie seizes the moment during the ball to seize the microphone and deliver an emotional speech. He reconciles his differences with Billy, wins over his peers, and bravely declares his love for Amelia. As their lips meet in a heartfelt kiss, they find solace in each other, moving forward into a new chapter together, full of unexpected twists and shared happiness.
