The film is set in a village named Kongankulam, located between Rajapalayam and Sivakasi in southern Tamil Nadu. It entails two different dreams of two different people for one person. The main aspects of this film are of the selfless, deep love and admiration that Maari develops for her cousin Thangarasu and the love and expectations of a poor, hardworking father to his son Thangarasu.

The film begins showing Maari happily married to her husband Karuppasamy, a small shop owner. She leads an uncomplaining life with a smile on her face at all shades of events, which fascinates even Karuppasamy. One day, she leaves alone to her village festival with the permission of Karuppasamy, who promises that he will follow her there after his business for the day has finished. When her mother asks why Maari came alone, she answers that she came early in order to see Thangarasu, much to her mother's dismay. On her way to see Thangarasu, she begins to reminisce of her past that includes her bold proclamation of her aim to be Thangarasu's wife from her school days – a time when they used to play together – that develops into her shy, unrequited yearning for him in her teenage years – a time when Thangarasu is an engineering student, while Maari works as a labourer in her village's fireworks company along with her best friend Cheeni, a practical girl who at first advises Maari to be realistic, but later, seeing her passion for Thangarasu, helps her out in many ways as she could. By that time, everyone in her village knows about her ardent love for Thangarasu except for him. After many attempts, she fails at trying to confess her love to him or to even talk to him openly without feeling shy while he is away in city or in her village. However, Thanagarasu comes to realise her love after many incidents where people he knows tells him of this.

At the same time, the film shows Thangarasu's father working as a cart driver and carrying labourer. He expects respect for his age from his young bosses and colleagues, but due to an unpleasant incident, he presumably thinks that being rich and owning modern items such as a car only will bring him respect. He takes pride in the fact that his son is studying to be an engineer and dreams of big things about him. However, Thangarasu breaks his castle in the sky by saying that once he starts working, unless he joins a renowned company, his salary will be merely Rs. 6000, not as large as Rs.35000 as software engineers earn, as he is just a mechanical engineer. This shatters the dreams of Thangarasu's father, who then resorts to alcohol and deems that he will never achieve the respect that he yearns.

Thangarasu's father is against the idea of Thangarasu marrying Maari as he believes that one cannot live happily and with respect just alone with higher education, but with money. Thangarasu, though initially after coming to know of Maari's faithful passion, begins to reciprocate her feelings, though after finding out that the son of his best friend who had married his cousin had birth defections, he finds it not a good idea to marry someone in related by blood. Therefore, heartbreakingly agreeing to marry the proposed daughter of someone from a wealthy family that his father approves of, thus choosing his father's dream. Maari too agrees to marry someone else on a condition that her mother and brother must attend Thangarasu's wedding as they initially refused to go after discovering that Thangarasu will not wed Maari. Maari happily marries while wishing that Thangarasu and his wife to become successful and Thangarasu to be happy just as she will try to be with Karuppasamy.

The current day sees Maari entering Thangarasu's house and seeing a car parked outside and Thangarasu talking to someone on a phone about business-related matters. Seeing her come, he directs her to go inside. She comes into the house and sees it decorated with latest modern devices. Nothing made her happier than seeing Thangarasu's wedding photo hung on the wall. She sees Thangarasu's wife in the backyard sitting on a chair and reading a novel. She goes up to her and talks. Initially nice, his wife sneers later at the question of possible pregnancy, making Maari shocked. She later witnesses in a hidden place that Thangarasu's wife treats him badly and shames him for marrying her shamelessly, a rich woman, when he himself is poor. Though begging his wife to stop shouting in fear that Maari may hear and knowing that she still lives for him and hearing this will terribly traumatize her, he sees that she is hiding listening to all of this with tears in her eyes. He then goes away with a shattered heart to his room, while Maari runs away and meets Thangarasu's father outside, who heeds to the situation seeing his arrogant daughter-in-law outside and his crying son inside, is also heartbroken. He explains to Maari saying, "We both had a dream that we wanted, but I did not stop to hear the dream of that girl, by this indirectly quoting that if it wasn't for him, Thangarasu, would not be in this unhappy marriage right now."

Maari flees from the scene and departs with her belongings back on the way she came, just as Karuppasamy touches his feet into the village. He discovers Maari too shocked to understand what had happened, sitting on a tree stump emotionless. Upon hearing no answers from Maari for why she is here and not at her home, he shakes her, and she starts wailing out loud, showing that her seemingly happy life led with Karuppasamy was all in hope that Thangarasu was also leading a happy life. Since he is not, it seems that she will lament for the rest of her life, knowing the sadness and pain of her lover, whom she cannot console.