This film starts with Karthik (Madhavan) frantically searching for his wife Santi (Shalini) in a railway station. As the local trains come and leave that suburban station, Karthik remembers his first meet with Santi and how that turned out to be a meaningful relationship and marriage. Karthik is an engineering college student in a city.
Santi is a medical student living in the same place. Their love started by observing each other while traveling.
As their love blossoms over a period of time, the couple informs their respective parents to talk with each other for the marriage proposal. Since Karthik belongs to rich family and Santi to a middle class family, there is some amount of friction in the talks which results in ego clash. Santi being a conservative girl decides to part with Karthik since the family ties are going to be strained. But the separated lovers could not keep themselves away from seeing each other That resulted in Karthik and Santi getting married to each other at a registrar office and keeping their parents in dark. Later on, when parents came to know about their kids secret marriage the hell broke loose that resulted in love couple being through out from their houses.
Then they start living on their own by doing jobs (these guys are graduated by now). After they started living on their own, there seems to be small misunderstanding cropping up due to the circumstances created by the nature. At one point of time Santi comes to know that her father is hospitalized. When she asks Karthik to accompany her to the hospital, Karthik rejects to go along with her as her father has slapped him in the past.
That evening she gets the news that her father is died. From that stage Karthik starts feeling uneasy in front of Santi thinking that he is indirectly responsible for her father's death. The devil of suspicion in Santi assumes dangerous proportions when she happens to see Karthik hug the sister of Santi in a public place. The reason for the jubilation of Karthik was entirely different. As the couple is entangled in a cold war of misunderstandings, Santi comes to know the reason behind Karthik hugging her sister. When the clouds of suspicion have passed away from the heart of Santi, she starts having uncontrollable excitement. She is going her way back to home and got hit by a car, On the other end Karthik is feeling tensed in the crowded railway station since Santi has not returned home and they had a big argument in the morning. Where is Sakthi?