Nirmala (Pallavi), an orphan Christian girl, lives in a convent and she wants to become a nun. She is sent to a village for becoming a nun. She joins, the church's father, Vincent Parker Soosai (Ramkumar Ganesan) and she works as a doctor until she becomes a nun.
She meets Muthuvel (Prabhu), an innocent youth, and they fall in love with each other. Rathnavel (R. P. Viswam) brings up his son Muthuvel without any affections and treats him like his worker, only his mother Vadivu (Vadivukkarasi) loves him. When Rathnavel arranges Muthuvel's marriage with his niece, Muthuvel and Nirmala reveal their love, Aranmanai accepts finally for their marriage with Soosai's help. Nirmala is eager for her wedding and leaves the village for taking with her the convent's sisters.
Rathnavel prepares the puberty ceremony of Rajalakshmi (Raasi), Muthuvel's niece, and manages to hide a Thaali inside a flower garland. Muthuvel, as an uncle, puts the flower garland around Rajalakshmi's neck and he gets married with her without knowing. Soosai complains against Rathnavel for arranging a child marriage but the complaint is withdrawn. The rest of the story is what happens to Muthuvel and Nirmala.