'Unns' is a story of romance and infidelity. Rituparna Sen Gupta falls in love with ad film-maker Sudanshu Pandey, but she is devastated when she finds out the Sudanshu is married. In a rebound reaction, Rituparna marries Sanjay Kapoor. Sajay Kapoor deeply loves her but she cannot reciprocate as she still carries bitter memory of her first love. While Sanjay is abroad on a bussiness tour, Rituparna meets Sudanshu at a party and they end up making love in his car. Sanjay is blisssfully unaware of his wife's infidelity and he continues as the loving and caring husband. Rituparna gives birth to a daughter but she is unhappy about the one-side love and files for a divorce. Sanjay does not want to give divorce as he sees no reason for the break-up. Aman Varma appears as his lawyer while Juhi Babbar appears as Sanjay's lawyer as she does not want the marriage to break. Sanjay wins teh case and Rituparna's parents also advice her to save the marriage.