Maddy, R. Madhavan, the carefree son of a small-town music shop owner Deen Dayal Shastri, carries a stubborn, rebellious streak that makes him uninterested in academics and hesitant about taking over the family business. His longstanding rival is Rajeev "Sam" Samra, Saif Ali Khan, a disciplined, model student who earns steady praise from teachers and friends alike. The two clash so repeatedly that Maddy even attempts to frame Sam. When Sam steps up to a challenge, the professors intervene, and at Sam’s graduation party, Maddy tries to provoke him again. Sam refuses, leaving college with a stark warning that the score between them will be settled someday.
Three years pass, and Maddy has softened only slightly. He works as a software instructor at a private company, still clinging to a carefree attitude. On a trip to Delhi, he sees a young woman dancing in the rain with children and, captivated, blurts out that she’s “my kinda girl.” This moment lingers when he later discovers she is Reena Malhotra, Dia Mirza. Their paths cross again in Mumbai, where fate seems to align in their favor—until he learns Reena is about to be engaged to Rajeev, a childhood friend living in the United States. Reena hasn’t seen Rajeev in years and doesn’t know what he looks like now, which gives Maddy a dangerous idea.
With encouragement from friends and his father, Maddy impulsively decides to impersonate Rajeev until the real one arrives. Over five magical days, he pours his heart into the ruse, and what starts as a foolish deception slowly blossoms into genuine affection. Reena begins to recognize her growing feelings for him, and for a moment, she lets herself be drawn to the man she’s getting to know. The moment of truth arrives just as she prepares to confront Rajeev with the truth, but the real Rajeev makes his entrance, and Reena’s trust in Maddy shatters.
The reveal creates a rift: Reena cancels the engagement, and Maddy’s attempts to explain himself fall short. To Maddy’s horror, Rajeev is none other than Sam, his old rival. Sam, furious to learn that his impostor is the man he despises, suspects the whole tale is born from their deep-seated enmity and refuses to trust Maddy’s intentions. Maddy tries to come clean to Reena, but she remains uninterested in a relationship built on deception. As her wedding approaches, Maddy and his friends confront Rajeev in a parking lot, though the plan is abandoned when Maddy realizes he is only causing more trouble. Rajeev goes back to Reena, and Maddy resolves to move on.
In time, Reena begins to see that, despite the deception, her feelings for Maddy were real all along—a realization Sam fails to grasp until the wedding passes. Meanwhile, Maddy accepts a job transfer to San Francisco, a move he initially resisted in order to forget the memories of Reena. When Rajeev witnesses Reena’s true emotions, he accompanies her to the airport. There, Reena and Maddy finally admit their love and reunite. Rajeev, though heartbroken, masks his pain with quiet pride, stepping away with the line, > "we can never be friends," before walking off. With obstacles behind them, Reena and Maddy move toward a shared future, their love triumphing over rivalry and deception.
