Idhu Kathirvelan Kadhal Full Story Explained (2014)

The film opens with a man being rushed to a hospital. The doctor says his condition will be known later. The story then goes back a few months. Kathirvelan, also called Kathir, is a young man from Madurai. He runs a minibus business. He has been a devout follower of Lord Hanuman since he was five. Because of his devotion, he has no interest in women or marriage. His family accepts this, though his father wishes he would settle down.

One day, Kathir returns from a Hanuman temple and finds his elder sister Vineethra crying outside their house. She had eloped with a Coimbatore mill owner named Shanmugham against their father's wishes. Their father had disowned her. Now, she has left Shanmugham and come back. Kathir convinces his father to let her stay. He then decides to go to Coimbatore to fix his sister's marriage. He lies to his father, saying he is going to Salem for business. Before he leaves, Vineethra warns him not to fall for Shanmugham's neighbour, Pavithra. She says Pavithra's father and Shanmugham are sworn enemies.

In Coimbatore, Kathir successfully resolves the conflict between Vineethra and Shanmugham. They reconcile, and Vineethra returns to her husband. But Kathir does not go back to Madurai. He sees Pavithra and falls in love with her, despite his sister's warning and his devotion to Hanuman. He takes help from his college friend Mayilvaganam, a doctor. They go to the Panasonic showroom where Pavithra works. Kathir tries to talk to her, but he creates a scene. Pavithra throws both of them out. She threatens to call the police if he follows her again.

Later, Pavithra learns how Kathir saved his sister's marriage. She forgives him and becomes his friend. But then she reveals she is in love with a businessman named Gautham. Kathir is heartbroken. To make things worse, Shanmugham finds out Kathir loves Pavithra. He kicks Kathir out of his house. Back in Madurai, Kathir's father also disowns him for lying. Kathir has nowhere to go. He moves in with Mayil.

Kathir soon discovers that Gautham is a womaniser. Gautham plans to have a one-night stand with Pavithra at a friend's wedding in Ooty and then dump her. Kathir warns Pavithra, but she does not believe him. She thinks he is still trying to win her over. But when Gautham tries to kiss her in his car, she realizes the truth. She dumps him immediately. She and Kathir reconcile. She now realizes she has feelings for him. With help from Mayil and Pavithra's Malayali friend, they confess their love.

But their families are against them. Pavithra's father and Shanmugham are enemies because of an old family feud. Kathir and Pavithra decide the only way is to make the two men reconcile. They hire a mimicry artist named Balaraman. He imitates the voices of both fathers. He tricks each man into thinking the other wants peace. The two men finally reconcile. Kathir's father still refuses to accept Pavithra at first. But when Kathir says he will not marry without his blessing, his father softens. He gives his permission. The film ends with Kathir and Pavithra getting married happily. The opening scene is revealed: Mayil had pretended to poison himself with laxatives to avoid Kathir's father's anger.