Powerful and poignant, this socially relevant drama revolves around Prabhakar (Jiiva), a Tamil teacher in a private school in west Mambalam area of Chennai, who leads a lonely life in a lodge. He is frustrated and even tries to commit suicide, in a system where knowing your mother tongue and teaching it is looked down upon by a society that is becoming increasingly westernised and materialistic.
The narration is mostly in a series of flashbacks. Prabhakar, for no fault of his, is at the receiving end, terrorized by cops and on the run after killing a railway booking clerk in a fit of rage. He roams all around the country and joins some saadhus, high on pot and also grows his hair long and keeps a shaggy beard.
Finally he wants to exorcise the devils within and at gun point kidnaps a television anchor Yuvaan-Suang (Karunas), who records his life story, where he confesses to killing 22 people in cold blood.
In the flashback he reveals his past, his upbringing by a Tamil teacher Poobaal (Azhagam Perumal) and his childhood sweet heart Anandhi (Anjali) who later in his life becomes an obsession for him. The love between Prabhakar and Anandhi is shown in flashes when Prabhakar is narrating his story to Yuvaan-Suang.
Prabhakar, the kid lives in a village. He develops a friendship with the neighboring girl, Anandhi. Anandhi's family relocates to another place after a few years after which Prabhakar's childhood is marred by tragic events as he loses his mother and grandparents in an accident. His father, a soldier, admits him in a boarding school and leaves. There he bonds with Poobal after some initial mischief.
Slowly, Prabhakar starts looking upon Poobal as his father. Years roll by and Prabhakar grows into a young man who develops an interest in Tamizh, his favourite teacher's subject.
After completing his 12th Grade, Prabhakar hears about the death of his beloved teacher Poobal, in an accident and travels to have one last look at him. There he sees Anandhi, his childhood sweetheart, whose father has also died in the same accident, in an argument with another family for having one look at her father's body.
Prabhakar enters into a fistfight and ensures that justice is done. This incident nurtures the love between Prabhakar and Anandhi. They meet regularly thence. Prabhakar joins college where his preference for taking up Tamil is ridiculed by his room mate and few others. Anandhi's mother does not object to her daughter's love for Prabhakar as she sees him as a source of financial support.
At one point, she sells his motorcycle for her expenses. Prabhakar does not mind it. After a few years, Anandhi and her mother are forced to relocate to Anandhi's uncle's house in north India due to monetary difficulties. Prabhakar initially loses contact with her but traces her back to her uncle's home.
Somehow, Anandhi finds Prabhakar and they share a poignant moment in her uncle's home where Prabhakar asks about her health to which Anandhi asks about the time of his departure. Prabhakar buys some clothes for her and leaves her promising that he will keep in touch. After few mail communications, Prabhakar again loses contact with her.
Meanwhile, Prabhakar gets a job as a Tamizh teacher and starts living in a lodge. He manages with a meager salary and loses focus in his personal life. On one night, he intimidates a call center employee who flees after failing to recite the Tamil verses which a drunken Prabhakar gives to him. It is after this incident that the encounter with a police inspector happens where they arrest Prabhakar for smoking in public.
Prabhakar is released and he tries to commit suicide, albeit unsuccessfully. The police again get hold of him and try to book him on false charges. Prabhakar manages to escape and then unintentionally kills the railway clerk.
Later, at one point in his life, Prabhakar comes in contact with Anandhi who has turned into a prostitute. He rescues her from the pimps after holding them at gun point. He plans to leave the city to his hometown along with Anandhi. He leaves her at a women's hostel after which the encounter with the television anchor happens.
The police get wind of Prabhakar and try to catch him in his hometown. Both Prabhakar and Anandhi hold hands and run towards an oncoming train committing suicide at the same place where Prabhakar's dog died during his childhood.