The plot is set in 1999. Arivu is a young cop who just got selected in the Tamil Nadu Police and is sent to the PRS (Police Recruit School) for training. He is joined by a few of his friends and soon befriends other trainees. A few among them are older policemen, who cleared their interviews in 1982, but due to political reasons, could not get placed till date. Most of the trainers see them as unfit old men and mock them. However, Arivu motivates them.

The PRS is run by Inspector Muthupandi, a stern but corrupt officer who is feared by all. One of his aides is Eshwaramurthy, a very strict and ruthless trainer, who has a record of winning all the parades and even resulting in the deaths of a few trainees in the name of very hard training (Extra Drill called as ED). On the very first day of training, one of Arivu's friend from the '82 batch faces the wrath of Muthupandi after he complains about the lack of toilet facilities in the campus. Soon, Easwara Moorthy starts seeing Arivu as a rival and warns him that he will not allow him to pass the training. He follows many tactics to brutally punish and demotivate Arivu and his batch.

How Arivu manages to win against all these odds forms the rest of the story.