A housewife's life changes drastically after becoming a radio jockey for the city's biggest radio stations.
Karthik (Prithviraj) and Viji (Prakash Raj) are close buds, who are keyboard players in music director Vidyasagar’s team. They are brilliant in their work of re-recording and background scores. They are fun-loving, witty and share a great rapport. They come to live in an apartment complex where they meet a handful of interesting people. Their neighbour and flat secretary, Ananthakrishnan (Brahmanandam) is not too happy about Karthik occupying the flat and asks him to vacate as bachelors are not allowed to live there. Preethi (Neelima Rani), a girl from one of those apartments, is head over heels in love with Karthik.
It is a story about a father and a son which is filled with sentiments or sorrow. Govindankutty (Mohanlal) is on a look out for his unknown father seeking to take revenge by killing him for leaving him and his mother. Then enters Anantha Subramaniam (Sivaji Ganeshan) a rich trader, who comes to Govindankutty's home-town and likes him instantly for his loyalty and honesty.
Uyir Mozhi is a sci-fi film that talks about the miraculous properties of DNA. The story is about 5 boys who fall in love with the same girl and the role DNA plays in their love lives.