Kannabiran is a lawyer at the Madras High Court who lives with his family consisting of his father Aadhirayar and mother Kosalai, in Thennaadu. Their neighboring village is Vadanaadu. Residents of both villages believe that god and goddess Shiva and Shakti originated in these villages and hold a grand festival celebrating their togetherness. Women in Thennaadu are married to men in Vadanaadu and vice-versa. However, when a woman from Thennaadu, who is married to a man from Vadanaadu, commits suicide, both the villages engage in rivalry. Kannabiran falls in love with Aadhini from Vadanaadu, and the two of them get married. Aadhini's friend Yazhnila is in love with Nithin. Nithin, who is Inba's henchman, cheats her by asking her to sleep with a man. Yazhnila tries to escape from Nithin's clutches but is chased and beaten badly by Inba's men.

Kannabiran comes to her rescue in the nick of time and warns both Inba and his men. Previously, Inba was responsible for killing his pregnant wife and a girl named Monika, who was killed and made it look like a car accident. After Kannabiran and Aadhini's marriage, Kannabiran gives shelter to Yazhnila and motivates her by standing beside her in the fight against the pornography racket run by Inba. However, when Kannabiran and Aadhini get intimate, their video is secretly shot by Inba, who also shoots a video of Aadhini bathing. When they receive the videos, they are both shocked and devastated. Despite all of the happenings, Kannabiran remains headstrong and requests Aadhini to stay strong and fight with him. Soon, he gathers all the victims of Inba's racket and files a petition against Inba and his men.

However, Inba's advocate produces false evidence, showing that he is a philanthropist and educationalist. As a result, the judge dismisses the case and orders the arrests of Kannabiran and Aadhirayar. After spending two months in prison, Aadhirayar motivates his son to turn into an executioner and to see beyond his initial beliefs in the law of India and order to deliver justice. Kannabiran readily accepts and kidnaps all the men working for Inba and locks them up in a factory. After a deadly and intense cat-and-mouse chase between Kannabiran and Inba, Kannabiran is able to get access to the systems that Inba and his men use for creating pornographic content and destroys them. Kannabiran ruthlessly beats Inba's men and lectures their parents on men respecting women and their privacy.

Kannabiran is able to prove that Inba and his men have intimate recordings of 500 women belonging to their village and are committed to spoiling the lives of those women by not letting them get married and driving off their dignity in society. Kannabiran also recollects his past when he was nine years old, his younger sister was taken by some people and brutally assaulted to death. The relatives of Inba's henchmen are now ashamed of them and kill them for their actions. Nithin is killed by his sister. Alagunambi, a professor who won the best teacher award, is shot dead by his wife. Aaron, another henchman, is killed by corrupt Police Inspector Faraday. Subsequently, Faraday is killed by Yazhnila's father, who earlier wanted to get justice for his daughter but was met with apathy by Faraday. As for Inba, he is killed by his father-in-law after Inba killed the latter's daughter and spread rumors after her death.

Kannabiran surrenders himself before the police and admits that he committed all the murders. Kosalai berates him for turning into a ruthless murderer even after witnessing his family's struggles and public humiliation. Kannabiran reminds her that he did not commit the murders, but simply removed the weeds that are harmful to society. He is arrested for the judicial killings, but the women of the village, knowing that he did the right thing demands his release.