A boy raised in a cemetery grows up with no social skills, and leads a turbulent life readjusting once he moves out of the cemetery.

Dheena works for his brother Adhikesavan, a gangster, and is very close to him. However, things turn sour between them after a misunderstanding leads to the death of their sister.

Satyam (Prabhu Deva) is the carefree son of businessman, owner of Satyam mills Lakshmipathi (Moulee). Disappointed Lakshmipathi asks Satyam to spend three months alone on the streets of Chennai to learn the value of money. He would have no money and could not use the information of who he is and his education (paid by his father) to gain favour or make a living from anyone.
So Satyam sets out and from the very start, meets Divya (Laila), who plays an overexuberant youth girl, who cries or laughs constantly. In the next frame, he saves Meenakshi ‘Meena’ (Neha) in the style of MGR from would-be rapists, and in the third, he meets Julie (Kalyani), they both take each other as siblings.

The movie is all about a group of five college friends — Shaam (Shaam), Imaan (Arya), Pooja (Laila), Priya (Asin) and Irene (Pooja). The friends gather for Imaan’s wedding, years after everyone has parted ways.
The movie starts with Pooja leaving USA to go to Imaan’s wedding. Meanwhile, back in India, everyone else is helping Imaan with the preparations for his wedding and catching up with their long lost college friends. The movie goes through series of flashbacks of old memories during their college days. Imaan and Irene meet for the first time, after a long time. The first flashback occurs. They were once in love; however it didn’t turn as Imman had expected it to be.

A young man tries to explain to his lover that her fiance is a crook. She refuses to believe him. Later, she realises her mistake and comes back to him. But the man now loves another woman.

Looking to put behind a past that haunts him, Nandha tries to reconcile with his mother and live life on his terms.

Dhill is the story about Kanagavel (Vikram), whose only dream is to become a police officer. He succeeds in passing the exams and wins a girlfriend Asha (Laila). One night after having dinner at a restaurant near the beach, Kanagavel goes to pay the bill, leaving Asha behind. At that moment a corrupt police officer Shankar (Ashish Vidyarthi) drinks and behaves indecently to Asha. He then attempts to assault her but is severely beaten up by Kanagavel, and he receives a scar on his face. Shankar, angered by this, seeks revenge against Kanagavel. Kanagavel kills Shankar and his goons.

Subramaniyam Siva (Ajith Kumar) is in jail, awaiting the death sentence for killing corrupt and evil members of the police force who had killed his father SI Ganapathy (Rajesh) and sister. SP of Police Nethiadi Nandakumar (Prakash Raj) is an honest, fearless and upright police officer who has been given the mission to flush out the terrorist outfit behind the Coimbatore blasts. He decides to employ unconventional methods to fulfill his mission and engages Siva to assist him, renaming him Paramasivan and giving him a single-point agenda – trace out and erase the people responsible for the Coimbatore blasts. Unaware to Paramasivan, Nandakumar intends on killing him after the mission is completed.