dhayaparar (chittoor v. nagaiah) is a widower whose only son sundar (sivaji ganesan) studies in a college at tiruchy. sundar is a tenant in a house in which sumathi (padmini) lives with her father. they both start liking each other and sumathi's father agrees to their marriage. sumathi's elder brother doctor gopu (s. v. sahasranamam) lives in bangalore and is addicted to racing. using this situation, his friend moorthy (s. a. ashokan) tried to befriend gopu's wife nalina (s. varalakshmi) but she rejects his advances. kandaswamy (friend ramasamy) working with doctor gopu, notices the happenings in the family and feels bad. gopu, in order to settle a loan, borrows money from moorthy after signing a mortgage letter. kandaswamy takes some money from that to clear all family dues and gopu dismisses him for that. moorthy comes home when nalina is alone and tries to molest her, but kandaswamy saves her. gopu arrives there realises his mistake and unites with nalini and takes kandaswamy back in job. after the exams, sundar leaves to chennai to get his father's concurrence to marry sumathi. after a few weeks, he writes to sumathi's that he will be coming in a week to finalize the marriage.