Laaga Chunari Mein Daag deals with one conservative relatively poor family and talks mainly about the eldest girl who takes up the responsibility of protecting and supporting her family financially. Badki (Rani Mukherjee) and Chutki (Konkana Sen) live a fun-filled life in Banaras. Badki is aware that the family is in dire straits, but she and her mother protect Chutki at all costs. When things get worse, Badki decides to go to Mumbai and seek a living for the family. Alone and unsupported in the midst of the urban jungle of Mumbai, Badki battles with dark forces, keeping her focus on her purpose to support her family and continue Chutki’s education. She deliberately morphs into someone else, leading a secret life full of murky compromises. When Chutki comes to Mumbai to work, things take a dramatic turn as she has to hide her secrets from Chutki. But her dual life is revealed, and the two sisters come face to face.Everything threatens to explode in their faces, destroying all of them.