| Director | Pa. Ranjith |
|---|---|
| Genre | crime film |
| Country | India |
| Budget | ₹15 crore |
| Box office | ₹44 crore |
Kaali is an impulsive and short-tempered working-class man who works in an IT company and enjoys playing football during his free time. His best friend is Anbu, a young political aspirant. They live in the dilapidated flats of a housing board in Vyasarpadi, North Chennai, along with their friends. In a long-standing bloody feud, two political party factions have been laying claim to a wall on which they can paint the portraits of their respective political leaders. Anbu, under the local leader of one of the parties, Maari, is determined to claim that wall for their party. Kannan, the chief's party, and his son, Perumal, are hell-bent on ensuring their opponent's efforts go in vain. The painting of Kannan's father, Krishnappan, has been on the wall for two decades since the start of the feud.
The two parties and their supporters get into frequent clashes and scrapes. In the meantime, Kaali falls in love with a politician's daughter, Kalaiarasi, but she remains indifferent to him. In a spur of motivation due to the upcoming elections, Anbu reserves the wall for their party. Although the wall is in their area and technically theirs, the opposition asks Anbu to give it up as the portrait of their patriarch's portrait had been there for quite some time. Moreover, since three people had previously been killed in connection to the wall, including members from both parties, people have started to consider the wall a bad omen. When Anbu declines, a goon of Kannan starts insulting Anbu, and Kaali attacks him, leading to Kannan seeing Anbu as the reason for Maari's resurgence. Kannan's henchmen plan to kill Anbu and Kaali. Kalaiarasi professes her love to Kaali.
When the henchmen try to kill Kaali and Anbu, they escape and hide behind a van. They see Perumal, who does not notice them, talking on the phone, giving orders to kill Anbu at any cost. Kaali then kills Perumal with a straight hit to the head using a crowbar. Maari instructs Kaali and Anbu to surrender at Kanchipuram district court to avoid being killed by the henchmen, but the FIR contains Anbu's name. Anbu takes responsibility for the murder and hopes to be released soon, but Kannan's henchmen hack Anbu to death and seriously wound Kaali outside the court. Kaali slides into a depression of guilt and swears revenge, attempting to kill Kannan. Afterwards, Kaali is berated for his bad temper by his parents and Maari, who want him to get his life back together. Maari assures Kaali that Anbu's death will be avenged. Kalairasi begins to comfort Kaali, and they spend time together and get married.
One day, Kaali and Kalaiarasi arrive at a restaurant, where he notices one of Maari's henchmen sitting at the nearby table. When he goes up to the henchman for a chat, the latter runs away in fear. After catching him, Kaali learns that Maari had joined hands with the opposing party to become MLA of RK Nagar and was the brain behind Anbu's assassination. Though reluctant, Kalaiarasi lets Kaali pursue his vengeance. At a local meeting where Maari is being felicitated, Kaali spills the beans, and the locals chase Maari out. Kaali splashes paint on the wall, thus ruining the portrait. Soon, everyone follows suit. Maari plots to kill Kaali but is betrayed by the touted successor of the opposing party. In a showdown, Kaali subdues the henchmen sent to kill him and grievously injures Maari, who is soon killed. Kaali and Kalaiarasi start teaching in the building whose wall was the cause of this bloody feud. The wall now has a theme of children's education painted on it. However, Kannan still wants to hang his father's portrait on the wall.