Somu (Ravichandran) studies with the help of his maternal uncle Dharmaligham Pillai (V. K. Ramasamy). He falls in love with the daughter of a Sivagnanam (Major Sundarrajan) i.e. Meena (Jayalalithaa). He marries her and stays in their house as Veettu Mappilai. Sivagnanam's wife (P. K. Saraswathy) does not like this and insults him indirectly. Her cousin-brother (T. S. Muthaiah) plots to usurp the wealth by his son Balu (K. Balaji), who is secretly married to Seetha (Udaya Chandrika). Somu spots Seetha, his presumed-dead sister while she is performing on stage. Not knowing they are siblings, Meena suspects Somu's fidelity. Balu and his father create problems between Somu and Meena. How Somu solves all the problems and paves way for a happy family reunion.