The movie begins with a trio of friends in college - Malar (Manasi Parekh), Mona (Maya), and Gayathri (Vibha Natarajan). Mona falls in love with Karthik (Shiv Panditt), despite the advice of Malar who suspects Karthik to be a complete flirt. One day, while on a date, Mona mentions Malar's views about Karthik to him, and this gets Karthik to start disliking Malar for interfering in his love life. When Karthik calls Mona, Malar accidentally picks up the call, and they get into an argument with Karthik venting out his anger towards her interfering in his love life. Shortly later, he breaks up with Mona. Gayathri, believing that Mona was a wrong choice in Karthik's life, begins to date Karthik, while Malar is firmly against it. The relationship ends the same way as his relationship with Mona.

A year or two later, both Karthik and Malar work at the same software company on different floors in the same building. One day, while trying to call his friend on Malar's floor, he accidentally calls Malar and the two realize their identities and presence in the building, and the age-old feud resumes. Over lunch, both Malar's friend Vicky (Santhanam) and his own friend Suja (Suhasini Raju) advise Karthik to sort it with Malar. Vicky questions why Karthik would fight with such a beautiful woman as Malar. Karthik, not knowing what Malar looks like, decides to take a look at her. When he sees Malar, he falls in love at first sight. He then tries to reconcile with Malar, but she is not willing to forgive a flirt like Karthik. Karthik becomes desperate and begins to follow Malar, and in a chance meeting orchestrated by Karthik, he introduces himself as a sweet and kind person by the name of Sundar. Malar, who has never met Karthik face to face, believes his false identity and begins to open up to Sundar. They start to get to know each other and meet often, when one day, Suja, who works with Malar finds out about Karthik's game. Suja gives Karthik the ultimatum to reveal his true identity once Malar declares her love for Sundar. Karthik tries to salvage his relationship with hilarious consequences. But, all said and done, how Karthik reveals to Malar about his true identity and her acceptance or rejection forms the crux of the story.