Bad Boy is a dubbed verison of Tamil movie Alex Pandian and its an action-masala film. The story revolves around Dr GKM and Alvin Martin, who wants to distribute fake medicines with devastating side affects in the state. In bid to get the CM's signature on the papers, they hire a local thief (Karthi) to kidnap his daughter.
The thief brings her and keeps her as a hostage in a forest. But the girl falls in love with him. What happens next will form the rest of the story.