| Director | Srinath Rajendran |
|---|---|
| Genre | thriller film |
| Country | India |
Engineering students Koobrin, Tharun and Ram become close friends after meeting in college. Despite their different backgrounds, they share a carefree attitude toward life, frequently skip classes and perform poorly academically. Tharun faces pressure from his family to succeed as an engineer, Koobrin joined the course only after being promised a motorcycle by his father, and Ram, though wealthy, has little interest in engineering. After being expelled from their hostel, the three move in with their easy-going lecturer Chandran and his dog, Koothara.
During college, Ram falls in love with Shilpa, while Koobrin has several short-lived relationships. When Koobrin discovers that his girlfriend Sheistha has been unfaithful, the trio publicly confronts her during the college festival, leading to their expulsion from college without completing their degrees.
Struggling to find direction, Tharun returns to his family's painting business, Ram fails at several jobs, and Koobrin is sent to a seminary to train as a priest. Feeling like failures, they decide to start an information technology company called Yellowtooth. After secretly taking money from their families, they invest heavily in the venture despite having no business experience. The company quickly accumulates debt and most of its employees resign. During this period, they become friends with their neighbour Swathi, a single mother, although Tharun initially resents her young son over a previous incident.
After deciding to close Yellowtooth, the trio meet a mysterious fisherman in a bar who befriends them and claims to be a cursed merman. He encourages them to enter the fishing business and persuades them to purchase an old fishing boat from an elderly fisherman named Usthad Sali. With Swathi's assistance, they mortgage Shilpa's property to finance the purchase without inspecting the vessel.
They discover that the boat, nicknamed AK47 or Aale-kolli ("man-killer"), is old, badly damaged and believed to be haunted, with a reputation for causing numerous deaths at sea. The mysterious fisherman is revealed to be Usthad Sali himself, who deceived them into buying the boat for far more than its actual value.
Having no alternative, the friends repair the boat and set out on their first voyage with Koothara. After failing to catch fish, they are caught in a violent storm and become stranded at sea. Usthad contacts them and reveals that abandoning them is revenge for their earlier encounter, leaving them with poison as an apparent means of ending their lives. During their ordeal, Tharun confesses that he previously had a relationship with Swathi.
Refusing to give up, the trio repair the boat, resume fishing and successfully catch enough fish to return safely to shore. They discover that Usthad has disappeared but has returned the money they paid for the boat. Inspired by their experience, they abandon fishing and revive Yellowtooth, eventually building it into a successful company.
Ram marries Shilpa, Tharun marries Swathi, and Koobrin begins a relationship with his former classmate Roshni. During a prank involving a hidden microphone on Tharun and Swathi's wedding night, it is revealed that Tharun is the biological father of Swathi's son.
In the closing scenes, Koothara narrates the story to his son, while Usthad is shown swimming with two mermaids, suggesting that he has finally been freed from his curse.