Vaibhavari Sahay, affectionately called Badki (Rani Mukerji), and Shubhavari Sahay, affectionately called Chutki (Konkona Sen Sharma) are the daughters of Shivshankar Sahay (Anupam Kher) and Sabitri (Jaya Bachchan). They live together on the banks of the Ganges in Banaras. Life is full of happiness and joy for the two, though the family is relatively poor. Badki especially is protective of her family and is determined to ensure Chutki completes her education.
As featured in the film, from {l-r} Rani Mukerji, Jaya Bachchan, Anupam Kher and Konkona Sen Sharma
As things go from bad to worse, Badki goes to Mumbai to find work. After encountering many obstacles and feeling desperate and out of options, she is forced to become the exclusive call girl "Natasha". Misleading her family — telling them she is an event planner — and sending them money for her father's medicines and to keep the family home from being foreclosed on, Badki hides her secret. Chutki completes her MBA and, unannounced, comes to live with Badki in Mumbai. The younger sister becomes a trainee at the Matrix Advertising agency, and Chutki falls in love with her boss, creative director Vivaan (Kunal Kapoor). Badki finds love in attorney Rohan (Abhishek Bachchan) but leaves him, afraid that he would be disgusted by her profession. Chutki inadvertently discovers what Badki does for a living.