Karthik Varadarajan (R. Madhavan) is an independent and free-spirited software engineering graduate establishing a software start-up with his friends. At a friend's wedding, he meets Shakti Selvaraj (Shalini), a student of medicine at Madras Medical College. They continue to bump into each other on local trains that they both use on their daily commute and eventually fallen in love. Karthik pursues Shakti aggressively and proposes marriage; Shakthi, however, is reluctant. Karthik manages to convince Shakthi and requests his parents to formally ask Shakti's parents for her hand in marriage; however, when the parents meet, they do not get along, and Shakti calls off the relationship altogether and leaves for an extended medical camp in Kerala.