Prabhu (Dhanush) is a happy-go-lucky guy who plays carrom in the streets, loses a considerable amount of his middleclass father’s earnings and indulges in a hopeless romance with a strange girl who he meets at a bus stop. When he is caught in the act of stealing a pittance from his father for booze with his friends, Prabhu questions his father’s responsibility towards his upbringing. His angry father gives Prabhu some of his savings and tells him to do something with his life. Prabhu purchases a bike (Bajaj Pulsar) instead and finds a job. The bike eventually saves his life from a freak incident and gets lost, subjecting him to interminable anguish as he searches for his bike.
Prabhu comes into conflict with the underworld, courtesy a brutal murder. Although he wants to stay away, Prabhu invariably gets dragged into rubbing shoulders with the criminals who now target his family to seek revenge.