Mayil is a 16-year old schoolgirl who lives in a village with Guruvammal, her mother. Guruvammal also takes care of a limping orphan who is dismissively called "Chappani" (Lame) by the villagers and does whatever he can to earn a living. Mayil's ambition is to become a teacher, and she hopes to marry a sophisticated, educated man; although Chappani is in love with her, she does not reciprocate his love.

Sathyajith, an urban veterinarian, arrives in the village to work and falls in love with Mayil. Believing that Sathyajith is the right person for her, Mayil falls in love with him, to the point of refusing an opportunity to attend a teacher-training course in Madras to remain with him. Despite loving Sathyajith, she does not allow him to exploit her sexually, which disappoints him. Never intending a serious relationship with Mayil, he proceeds to his native place to marry another woman. When Mayil begs Sathyajith not to leave her, he says he befriended her for pleasure—not marriage.

A dejected Mayil confesses about her relationship with Sathyajith to Guruvammal, who quickly plans to betroth her to someone else. The village ruffian Parattaiyan—who lusts for Mayil—spreads rumours about her relationship with Sathyajith. Because of this, Mayil's engagement plans are halted and the village becomes hostile to her. Unable to bear the shame, Guruvammal dies and leaves Chappani to take care of Mayil.

Chappani takes good care of Mayil, cheering her up when she needs it. She warms to Chappani, making him more confident and assertive and grooming him and his manners, to the surprise of many in the village. Mayil tells him to slap anyone calling him "Chappani" and to respond only to those addressing him by his name, Gopalakrishnan. When Sathyajith and Parattaiyan dismissively call him "Chappani", Gopalakrishnan slaps them. Mayil and Gopalakrishnan celebrate his newfound courage. An insulted Parattaiyan later beats Gopalakrishnan badly. Mayil saves him and spits on Parattaiyan in revenge.

Mayil decides to marry Gopalakrishnan, and sends him to the nearby town for buying wedding supplies. Learning of Gopalakrishnan's absence, Parattai goes to Mayil's house and tries to rape her. Gopalakrishnan returns to Mayil's house and pleads with Parattaiyan to leave her. When Parattaiyan refuses, Gopalakrishnan kills him with a rock and is arrested. He promises Mayil that he will return, and she waits every day for him.