Kalyanam is a family centric drama mixed with crime thriller. It has two tracks, one a family oriented and the other being a crime murder at the flashback, but both are interrelated.
The story begins with a search of a boy for the heroine Anandhi by her father Varadharajan and the suitable match Raghu was found. Everyone was happy except except Elango, who was lusting for his sister-in-law. He tries all the manner of tricks to spoil Anandhi’s wedding.
In the course of time, during Anandhi’s engagement, Raghu’s grandfather is killed in an accident. Therapy Raghu’s family calling off the wedding saying that she would bring ill luck to Raghu’s family.
With this turn of events, Another couple who has seen Anandhi in a temple tries to make her as daughter-in-law. Varadharajan and his family are elated about this proposal from the wealthy industrialist. But Anandhi has not come out of the cancellation of her terms of engagement with Raghu, with whom she is fond of. But reluctantly agrees to marry Parthiban.
Whether Anandhi marries Raghu or Parthiban and how the murder in the flashback is going to affect either of these three lives is the plot of the story.