Ashwin (Jiiva), a photojournalist, while covering the state elections, exposes corrupt politician Alavandhaan (Kota Srinivasa Rao) and Yogeswaran (Prakash Raj). This primes to his classmate, Vasanthan (Ajmal) emerge into power, creating a strong impact in youth politics across the state. But, soon Ashwin with his girlfriend Renuka (Karthika Nair) while investigating their friend Saro’s (Pia Bajpai) murder, find out that Vasanthan has links with Naxalites. How he exposes Vasanthan forms the story.
The movie went on to become a blockbuster, receiving a massive praise and applauds from the audience as well as critics. “..Jiiva, after some good work in ‘Raam’, ‘Katradhu Tamil’ and ‘Siva Manasula Sakthi’, gets a character-driven role in ‘Ko’, and comes out with flying colours..” quoted Times of India. “..Jiiva as Ashwin once again proves that he is a versatile actor. The body language and obsession of a photographer to click pictures are brought out well by Jiiva and we wonder if anyone else would have done this role as well as he has…” stated Behindwoods.com review.
The soundtrack album was scored by Harris Jayaraj, that received high praises and mentions across the music charts. Opening song ‘Aga Naga’ featured special appearance by many celebrities including Suriya, Karthi, Harris Jayaraj, Jayam Ravi, Tamannah, Jai to name a few. Song ‘Ennamo Aedho’ topped the charts for many weeks and went on to become one of the greatest hits. The film’s total worldwide collection at the time of release was ₹ 25 crores at the box office thus being biggest blockbuster ever in Jiiva’s career and completing a 100-day run at the box office.