[3] Vijay is a carefree youth, who is sent by his father ACP Deenadayalan in Ooty to work and become an responsible businessman.

Devaraj is sent to prison in order for his brother to appoint the lawyer Karnaa, who is disabled and Vijay's doppelganger.

Deenadayalan discloses the truth to his wife Lakshmi, who wants to bring back her son Karnaa at any cost.

Devaraj shows his secret illegal business to Karnaa, and Vijay takes some photos of his factory.

While filming the climactic action sequence, stuntman Sahul wanted to try out a bike stunt in a manner inspired by Jackie Chan.

[citation needed] K. Vijiyan of New Straits Times wrote, "Karna turns out to be a neat package of sentiment, love, action and songs".