Bachelor Rahul Malhotra (Aamir Khan) has just heard the news of the tragic passing of his sister and brother-in-law, through their lawyer (Tiku Talsania). He has inherited their business; two sons and a daughter. He finds the business in chaos under the "Japanese" trained Manager, Bhagwati Prasad Mishra (Mushtaq Khan), and the nephews and nieces - uncontrollable. His efforts to make sense of the business are met with even more challenges; and his efforts to find a suitable nanny are frustrated with one nanny after another quitting after being subjected to abuse at the hands of the three children. One day the children sneak out to a fair, and meet with runaway, Vaijanti Iyer (Juhi Chawla), who has refused to marry the man of her father's choice. The children and Vaijanti make a hit with each other, and they sneak her into Rahul's house. With the three, Rahul's hands were full, now with the fourth addition, how is Rahul to handle his life; his love-life with Maya (Navneet Nishan); the business; and Mr. Mishra?