Singaravelan "Velan" lives with his widowed mother Parvathy in a village. Velan's father died heartbroken that his marriage with Velan's mother was not accepted by her sister-in-law and they had broken all links. Further, they believe that it was Parvathy's curse that killed her brother and sister-in-law in a car accident and they get a promise from the guardian that their daughter should not be married to Parvathy's son. Velan's mother reveals that it is Velan's duty to marry her brother's daughter Sumathi to reunite the separated family. Armed with only a picture of the girl when she was four, he leaves for Madras to fulfil his mother's wishes.
Velan arrives at his friend Mano's house to implement his mission. Mano lives with three roommates: Mani, Subha, and Ramasamy. Velan explains his mission, and all of them agree to help him. At a computer centre, the clerk generates an image of the adolescent Sumathi. While at the beach, Velan and friends recognise a woman playing tennis as Sumathi. When Sumathi goes to fetch her ball from the sea, Velan goes to help her. He accidentally submerges her but manages to pull her out of the water. After regaining consciousness, she berates Velan as she knows swimming. Despite his friends' advice to leave Sumathi due to her arrogance, Velan refuses.