The film is narrated in a nonlinear manner.

In the present, Arjun is a London-based DJ, leads a happy life. Also, there is Anu, who is pursuing her MBA in a London university. One day, Arjun is forced to come to his native village in Karaikudi to ensure that his ancestral property is not sold in an auction. Also, Anu too is forced to come to Karaikudi to meet her father, who is injured in an accident. The two strangers meet in a train. There begins their journey towards their respective destinations. Meanwhile, a diary of Arjun's father pops out from his bag. He browses through it to understand his father's love life.

In flashback, the movie goes back to 1985. It is revealed that Sekhar returns to his village after getting selected as a police officer. Sekhar falls in love with Meenal, but when their romance is revealed, Sekhar's family resists the relationship due to class differences. A dejected Sekhar leaves to begin training as a police officer. There, he becomes acquainted with Ammaiyappan, a young colleague. He learns that Ammaiyappan is in love with his uncle's daughter. A sequence of events reveals that both men love the same girl, Meenal, who in turn loves only Sekhar. After learning that Sekhar and Meenal are already in love with each other, a heartbroken Ammaiyappan attempts suicide. Feeling guilty for hiding about his love from his friend Ammaiyappan, Sekhar breaks up with Meenal and leaves his village forever leaving Meenal heartbroken.

Returning to the film's contemporary setting, we find that Arjun and Anu, after crossing several hurdles in their journey, reach their respective houses. They then realize that they have fallen for each other. Meanwhile, the film employs a Deus ex machina in the form of Anu's father to ensure that all story arcs are resolved. When Anu's father Ammaiyappan realizes that Anu is in love with Sekhar's son, he tells Anu that Arjun's father Sekhar was his old friend who had sacrificed his own life and happiness for Ammaiyappan's well-being, adding greatness to their friendship. Regretting his past mistake, Ammaiyappan immediately approves of their relationship and advises Anu to go after Arjun. On learning about Arjun's love for her, a happy Anu rushes to the airport with Ammaiyappan, succeeds in stopping Arjun and happily unites with him. It is implied that Anu and Arjun are then to stay happily together.