Deva (Ajith) and Shiva (Ajith) are the twins. Deva, the elder, is deaf and mute. But he is a genius, an expert at lip-reading and the head of a successful advertising company. Shiva loves and trusts his brother. Priya (Simran) wants to marry only someone who is an ex-smoker, an ex-drunkard and ditched by a girl but still pining for her. Learning this, Shiva invents an old romance between him and Sona (Jyothika) and finds his way into Priya's heart.
Deva meanwhile chances upon Priya and becomes obsessed with attaining her. His obsession continues even after his younger brother gets married to the girl of his dreams and he devises various means of getting close to Priya and keeping Shiva and her separated. Some of the methods Deva uses to woo Priya are masochistic (wounding his hand by the running car engine to stop the couple's first night) and psychotic (trying to kill his brother in so many ways). Priya realises the not-so-honorable intentions Deva has towards her but Shiva refuses to believe her and has full faith in his brother. What will happen next?