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 married to 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 secretly married to Seetha (Udaya Chandrika). Somu spots Seetha, his presumed to be dead sister while she was performing on stage. Not knowing they are siblings, Meena suspects Somu's fidelity. Balu and his father creates problems between Somu and Meena. How Somu solves all the problems and paves way for a happy family reunion.