 Khushi (Rani Mukherji) is a petty thief and a con artist, partnering with "Chacha" (Sadashiv Amrapurkar) and "Chachi" (Shashikala), a homeless and alcoholic couple. On a chance encounter with Ranbir Malhotra (Ajay Devgan), she finds out about a bunglow that he is building, which has not yet been occupied. She locates the bunglow and moves in, informing everyone that she is Ranbir s fiancee. She meets with the Malhotra family, who welcome her with open arms, and also meets with Pooja (Sonali Bendre), with whom Ranbir is in love with. When Ranbir returns, at first he is outraged at Khushi s intrusion into his life, but then decides to play along with Khushi to make Pooja jealous, little knowing what this playing around will do to his family; Pooja; and to Chacha and Chachi.