The film opens with a man (Aravind Akash) and woman interviewing civilians on love and the opposite sex. After a mixture of answers, they cease their questions, and the credits roll. The credits end as a boy, after being rejected by his girlfriend, is accidentally hit by a passing car and dies. Karthik (Vinay) walks off, disturbed, to his girlfriend Jhansi's (Sadha) office. There, he is criticized by her for his antics with other women and his lack of passion for their love. She walks off, ending their relationship.

Karthik is then shown as a civil engineer in Chennai, still playful and fun-loving. Accepting a request from his manager to go on a six-month business trip to Melbourne, he bids farewell to his friends Raju (Raju Sundaram) and Sathish (Sathish Krishnan). On the plane, he encounters a playful, flirtatious girl named Deepika (Tanisha), whom he sits next to during the flight. After spending hours together, they become friends and exchange contact details. However, by coincidence, Deepika is travelling to Melbourne to work in the same company as Jhansi, who is settled there. Together they seem to conveniently bump into Karthik at every corner, prompting an unwelcome reunion for Jhansi and Karthik.

While Deepika takes a liking to Karthik, Jhansi ignores him, even though he has hopes of getting back together. At a restaurant, Karthik bumps into a fellow Tamilian named Vaidyanathan (Srinath) and explains his love for Jhansi. The story then flashes back two years. Karthik had met Jhansi at a festival in a temple, where she played a prank on him and his friends. Taking a liking to Jhansi, Karthik begins to follow her intentionally, hoping for her to fall in love with him. Soon after, she becomes more and more suspicious of Karthik. This comes to a head when Karthik acts as the boyfriend of Raju's girlfriend Pooja (Paloma Rao), only for Jhansi to get confused and mistake him. His reputation as a trusting boyfriend takes another turn for the worse, when at a wedding, the bride (Lekha Washington) gives him a kiss after he improvises a song.

As the pair have a love-hate relationship, the breakup beckons when Jhansi sends her friend (Vasundhara Kashyap) undercover to flirt with Karthik. However, he lies by claiming that he was at home ill, prompting Jhansi to end their relationship. At the end of the flashback, Vaidyanathan suggests to Karthik that it is more important to move on than think regretfully, and Karthik gets over his relationship with Jhansi. However, finding out about Deepika's love towards Karthik, Jhansi becomes jealous and reinstates her love for Karthik. Soon, as she sees Deepika and Karthik's compatibility and understanding her fault, she finally understands what went wrong in their relationship. Then, Karthik tells her through a meaningful conversation that he still loves her, not Deepika. After this, Jhansi runs away to Sydney surreptitiously.

At the end of the film, the male interviewer who appeared at the start questions Jhansi on her decision to leave anonymously; however, she refuses to answer at first. Later, she replies that though she still loves Karthik, she was unable to understand him well. She knew that it would not work out and that she did not want to hurt Karthik further, thus becoming the sole reason for her departure. She then confirms that she met up with Deepika recently, and had found that she is married to Karthik and they have a child. She then walks away, claiming that her future lies in her own hands, and she is happy the way she is now.