The story begins with the funeral of Tina (Rani Mukherjee), who wants her new-born daughter - whom she names Anjali - to know her even though she won't exist any longer. In order for this to happen, she leaves her new-born daughter 8 letters, one to be presented to her on every one of her first eight birthdays. They slowly unfold the story of the lives of three college-mates, Tina, Rahul (Shahrukh Khan) and Anjali (Kajol). The eighth letter, though, reveals to her that it was her duty to bring Rahul & Anjali together, who were the best of buddies. Rahul did seem to have feelings for Anjali, but she, being a tom-boyish character, could never show her feelings to him clearly. Rahul, though, soon fell for Tina - the principal's daughter who arrived from London - least realising Anjali's fate.
At this point, Anjali realised just how much she loved Rahul. Tina had always been suspicious about this love, but could not be sure of it. Anjali, the heart-broken lover, decided to move far away from Tina and Rahul's lives during her exams, trying to make her feelings for Rahul latent. Though she tried her best, she could not hide her deep and endless love for Rahul from Tina, who was sure of this by the time Anjali was at the train station, leaving them for ever.?
Anjali Jr. is extremely touched by this love story, and decides to get the two together. Soon, with the help of her Nana (Anupam Kher) and Dadi (Farida Jalal), the obedient and lovable daughter of Rahul gets the separated best friends to meet. After about a decade, Rahul and Anjali Senior see each other, too much in state of shock to be able to even speak to each other. Soon, their love for each-other arises once again.?
After they are re-united, however, a new problem arises. Now Anjali Sr. (although she still loves Rahul) has been engaged to Aman (Salman Khan). What happens thereafter? Well, just watch the movie!