Indian Army Major Kathiravan is working on anger management issues under chief psychiatrist Rathi Devi aka Rathi in order to return to his job. Soon they both fall in love where she counsels him to leave for his village to spend time with his father Rangaswamy and sister. Though having hated his father due to his habit of borrowing money, Kathiravan reluctantly agrees. Kathiravan finds that his sister's fiancé Kesavan's family demands them to bear the marriage expenses. He realizes his mistake of abandoning his family and promises to fulfill his sister's wish. Kathiravan returns to Chennai to apply for a loan, only to get rejected everywhere. With the advice of his uncle, he takes his father to Chennai along with him and tries to get a loan in Rangaswamy's name and is also rejected everywhere due to financial security.

They are approached by a person, who claims to be a loan agent and tells them to forge documents to get a loan for a commission. Kathiravan initially refuses, but reluctantly agrees to the man's offer and submits all the original documents to him. The person helps them to obtain a loan of ₹6 lakh (US$7,500). Kathiravan is overjoyed and starts the marriage preparation. Later on, when Rangaswamy was unable to withdraw money due to insufficient balance, he informs Kathiravan, who in turn is surprised by the missing fund. Kathiravan enquires the bank, but to no avail. He becomes frustrated and scolds Rangaswamy. Unable to bear the words, Rangaswamy attempts suicide. In the hospital, Kathiravan learns that Rangaswamy took debts to extend Kathiravan's sick mother's life. He feels remorseful after hearing this and reconciles with Rangaswamy.

On Rathi's advice and with the help of his friends in the military, he decides to the track down the person responsible for the theft. Kathiravan manages to apprehend and chase a loan agent similar to his loan agent in order to extradite information. Later, he gets a phone call from a private number who tells Kathiravan to release him as he knows all the details about him and even threatens to release the private files in his sister's phone on the net. This shocks Kathiravan, who leaves the agent, but the agent is fatally hit by a van. The mysterious person is later revealed to be Sathyamoorthy aka White Devil, who is the kingpin of the Dark Net by the use of the Y2k Problem. He runs an educational trust as a front for his cybercrime network. Kathiravan tracks and confronts Sathyamoorthy where the latter reveals his knowledge of the former following him and tells him that he attacked his sister.

Sathyamoorthy also tells Kathiravan that he put ₹10 lakh (US$13,000) to his account from a flagged account for which he is court-martialed. However, Kathiravan tracks Sathyamoorthy's henchmen with Rathi's help and confronts Sathyamoorthy at the server farm, where the two engage in hand-to-hand combat. Sathyamoorthy defeats Kathiravan and burns the money due to his god-complex. All the people who were conned by Sathyamoorthy learns about Sathyamoorthy from Kathiravan, and they reach the docks. Kathiravan fights back and defeats Sathyamoorthy, where the people get their money transferred back to their respective accounts. Sathyamoorthy is arrested by the police but creates a new username named Dark Angel hinting a sequel.