Popular Anjali Sharma and dorky Rahul Khanna are best friends in St. Xavier's College. The college principal Mr. Malhotra has a handsome son Aman, who comes to St. Xavier's from London to finish his degree. He becomes friends with both Rahul and Anjali. Soon Rahul realizes that he is in love with Anjali, he is encouraged by his motherly housekeeper Rifat Bi to tell her so. Instead, Rahul is left heartbroken when Anjali tells her that she loves Aman. Rahul decides to leave college and shares a tearful goodbye with Anjali, going away from Anjali and Aman's lives forever. Aman then realizes that he came between two best friends who actually loved each other. After college, Anjali marries Aman and, in a year of marriage, Anjali gives birth to a baby boy. Aman is diagnosed with cancer and has little time left, so he writes eight letters to his son (one for each of his first eight birthdays), so that he will know his father. Before dying, Aman asks Anjali to name their son Rahul.
Eight years pass, and Anjali is a single parent living with her son and loving mother. On his eighth birthday, little Rahul Sharma reads the last and most important letter that his father left him; it tells the story of Rahul Khanna and how he was always Anjali's true love. Rahul Sharma is given the mission of reuniting Anjali with Rahul Khanna and bringing back Anjali's lost love. Rahul Khanna is no longer the dork he was in college; he is now more macho, and is engaged to Tina Mehra. However, he explains to his mother that he does not really love her and is marrying her as a compromise as he feels he can never love again after losing Anjali. Tina also suspects that he does not really love her. Rahul Sharma and his grandmother search for Rahul Khanna and soon learn that he is going to be working at a summer camp. They travel there, with a plan to later lure Anjali to come as well, and the two Rahuls meet each other. One night while watching television, Rahul Khanna realizes he has met his best friend's son, and that Aman is dead. Anjali soon arrives at Camp Sunshine, where she and Rahul Khanna are surprised and delighted to see each other again, sharing a sweet reunion. Throughout the days spent at the camp, Rahul and Anjali feel themselves falling in love. However, Rahul remembers that he is engaged and feels guilty. Tina arrives and tells Anjali that she is Rahul's fiancee. Anjali is heartbroken but congratulates Rahul. He takes this as her rejecting him again, so he leaves summer camp and decides to get married to Tina as soon as possible.
After seeing Aman in a dream, Anjali and her family go to Rahul's wedding, where Anjali silently confesses to Rahul that she loves him, and watches in tears as he is brought forth for the wedding. Realizing this, Rahul is hesitant to go on with the marriage, and stands weeping. Tina notices the tears in his eyes and realizes that he has always been in love with Anjali. She releases Rahul from the engagement and tells him to marry Anjali. Rahul and Anjali have an emotional hug and as the two marry, little Rahul has a vision of Aman smiling and giving him the thumbs up.
