Per Sollum Pillai has Kamal Haasan, Ramu as an orphan, who is adopted by a wealthy family. He gets adopted into the family when he saves the entire family from being deliberately poisoned by a miscreant. Rajalakshmi, the mother of the family, raises him as one of the family even though others outside the family see him as a servant. Ramu helps to run the family smoothly and looks after his step-parents, brothers and sisters like his own. Kamal intervenes whenever his step-brothers attempt to commit mischief in the family and thwarts all their plans. He tries to advise them to be resourceful but they hate him for that. A smuggler becomes an enemy to the family when Ramu intervenes and stop in getting his step sister married to the smugglers son. The smuggler kills Rajalakshmi in a climax scene and Kamal tries to save the others. Years later, Rau believes his daughter is a reincarnation of his step mother and lives happily ever after.