Dhanush is an impoverished youngster who makes a living out of selling milk tea, carrying the business on his bicycle. He falls in love with a college student played by Sridevi Vijaykumar. Gradually, the girl also reciprocates the boy's feelings and things go smoothly for a while.
The girl's parents find her a groom who is well educated and earns handsomely. The girl is in a dilemma on whom to choose as her life partner. She thinks of her future if she chooses the poor man where she visualizes herself giving birth to a child in a government hospital, her husband unable to raise the required funds for her medical expenses and overall a very difficult life. Contrast this with a life where she is pampered by everyone, her every need taken care of almost instantly if she chooses to marry the groom selected by her parents.
While the poor lover guy is on a religious trip to Sabarimala, the girl decides to marry the groom (Kunal) so that she can continue to lead a comfortable life. The lover is devastated when he hears this, and heartbroken when the girl goes to the extent of slapping him when he accuses her parents of changing her mind.
In a unique way, the poor man files a case against the girl for not holding the promise made to him of sharing a life together for a good 50 years. Though strange, the case soon gathers momentum and has the public discussing it everywhere. As the case progresses, several sacrifices made by him :for the sake of the girl come into light through revelations made by people known to him and by his close friends. The girl has a change of heart and on the final day of the hearing, decides to reunite with the guy.
In a final twist, when the girl offers a rose to him, the hero refuses to accept her saying that the case was filed not to win her back but to teach a lesson not only her but to every girl with an attitude identical to her. He justifies further by saying that yesterday she hated him because of his status but today she loves him and tomorrow she may again find him unattractive. Feeling light at heart, he leaves the court complex much to the surprise of the visibly embarrassed rich girl.