A triangular love story set on back drop of Simla. Sonia is an orphan girl residing with her uncle aunty and cousin Shila. Naturally she is the dejected individual in the family while Shila is stylish and beautiful. The tom boyish Sonia is forever on the receiving end a continous scuffle occurs amongst the cousins until one day Shila says that no man would ever get attracted towards Sonia and Somia throws a challenge at Shila that not only would she become beautiful and attractive but she would also snatch Shila's fiance Dev Kumar who is about to arrive in Simla in couple of days. Dev arrives but Sonia doesnt reap rich dividends and Sonia's grand mother comes to help. She grooms Sonia to a beautiful swan from an ugly ducking. This trick works magic and Sonia turns into a graceful damsel. Shila's conservative and apportunist attitudes and Sonia's attractive funny traits make the romantic Dec attracted towards Sonia. Sonia accompanies Dev everywhere in Shimla. The mission which she took up as a challenge soon turns into true and deep love. Ultimately Shila discovers the truth that her sister has a huge love over the issue and Shila begs Sonia to return her love. A shattered Sonia gives a word that she would leave Dev and Sonia starts behaving badly with Dev. Dev fails to understand why sonia has changed. Sonia abondons the house the very next day writing Dev a letter that if he did not marry Shila within days she could commit suicide. Dev and others make a unique plan to bring back Sonia and they conduct a false marriage ceremony. Through commentary over the radio Sonia hears the entire episode in her hideout and feels that the marriage has been conducted. Dev finds out Sonia's hideout. Shila realizes the love and sacrifces in the end.