Pavithram

Easwara Pillai (Thilakan) and Devakiyamma (Srividya) has two sons - Unnikrishnan (Mohanlal) and Ramakrishnan (Srinivasan). Unnikrishnan is an executive, engaged to marry Meera (Shobhana) and is under pressure to take the reins of her father's business empire. Ramakrishnan, a doctor, is unhappy, childless & has a nagging wife. Unexpectedly, Devakiyamma gets pregnant at her late age. Unnikrishnan is forced to be a surrogate parent to his new sister, whom he takes care of as his own daughter. (Summary by iceblox)