Plot
Agan and Kuralarasi alias Kural are cousins who share a close bond and run an event-planning collective called Surprise Dude, which organises surprise events for weddings, anniversaries, and proposals. Their friendship is warm and playful until Kural unexpectedly confesses her love for Agan. Startled by the proposal, Agan rudely rejects her, claiming he sees her only as a friend and part of his family, and she perceives that Agan has no romantic feelings for her. He also tells Kural that he will never develop feelings for her. To escape the pain of the rejection, she goes to Bangalore for her higher studies. However, after few days, Agan meets with an accident and realises he loves Kural as well and decides to confess his feelings.
Seeking approval, Agan visits Kural’s father, Athiyamaan, a powerful minister. To Agan’s surprise, Athiyamaan immediately accepts the proposal and begins making arrangements for the wedding. Kural is unaware of this as Agan did not ask for her consent before speaking to her father. When Kural, who had gone to Bangalore for her studies, returns home for her wedding, Agan is filled with excitement on the eve of the ceremony and is bashful. He sets out to Kural’s house to see her.
However, things take a different turn when, while Agan forcefully tries to kiss her, Kural stops him. He then notices that she is deeply distressed and on the verge of attempting suicide by hanging. She confesses that during her time in Bangalore, she fell in love with Paari, her dim-witted classmate. When he perceives that Kural no longer has any feelings for him, Agan, who struggles to control his sadness, accepts it and eventually promises her that he will help reunite her with Paari. Kural is unaware that Agan has feelings for her, as Agan passes off the kiss as a joke.
Later, Kural admits to her father that the man she loves belongs to another caste. Athiyamaan fiercely opposes the relationship. He then reveals a horrifying truth: to protect his political reputation, he once killed his younger sister who was also named as Kuralarasi as she had a relationship with a man from a different caste—a crime he also concealed.
On the day of the wedding reception, Paari attempts to elope with Kural with help from Agan, but they cancel their plan upon seeing Athiyaman's political influence all over India. Since Paari lacks a passport, their plan to flee abroad fails, forcing them to fake the wedding, and Kural and Agan get married. Following his wedding to Kural, Agan helps her and Paari escape to Thailand, but the plan collapses when immigration officers demand for return tickets as well. They devise a new plan to escape to Canada, with help from Agan's ex girlfriend and her husband who are settled in Canada. Paari's visa gets approved, but Kural's is rejected when her medical report shows that she is pregnant with Paari's child.
Desperate to continue their escape, Agan suggests abortion, despite Kural's resistance. A gynecologist warns that Kural's uterus is weak and that abortion could cause future miscarriages. Agan withdraws his suggestion, but Kural insists on proceeding. When Agan threatens to reveal everything to Athiyamaan so that she doesn't go ahead with the abortion, Kural reluctantly abandons the idea. She gives birth to a baby boy with six fingers. Agan, still devoted to her, poses as the child's father to handle official paperwork and care for the infant.
On the night of Kural's rescheduled departure, Agan's friend shames Kural and reveals that Agan had always loved Kural but stepped back when she confessed her love for Paari. Kural, who thought Agan was doing this as a friend, and unaware of his feelings for her, is deeply moved. During the ride to the airport, she confronts Agan and promises to find him a wife before leaving. She files for divorce from him and begins searching for matches for him through matrimonial websites and dating apps, but every attempt fails. Determined to fulfill his promise to send her abroad, Agan enlists a female colleague, Samyuktha, to pretend to be his girlfriend, which helps finalise the travel paperwork.
Athiyamaan eventually discovers that Kural and Agan have divorced and summons Kural. When she arrives, he confronts her about the separation. Agan intervenes, taking full responsibility for the divorce and claiming he intends to remarry. Infuriated at being publicly embarrassed, Athiyamaan assaults Agan and orders his men to kill him. When Kural learns of this, she confesses everything to her father, who, enraged, takes her baby son to kill him. Agan rushes to save the toddler. In a remote area, just as Athiyamaan is about to commit the murder, he suffers a heart attack and collapses.
When Athiyamaan regains consciousness in the hospital, the doctors reveal that he was saved by his grandson who crawled all the way to road and caught the attention of passerby who rushed them to hospital. Agan confronts him and makes him understand the value of love over his reputation and caste image. Realising the magnitude of his crimes, Athiyamaan apologies to his sister - Agan's mother, publicly confesses to the murder of his younger sister after 32 years and is imprisoned. It is revealed that it was actually Agan who saved Athiyamaan, but he lied that the baby saved him to change his heart and help him accept Paari.
In the post-credits sequence, Agan’s mother surprises him. She reveals that Agan and his colleague Samyuktha, who had once pretended to be his girlfriend, have genuinely fallen in love, and their marriage has been arranged. The film ends with Agan finding closure in love, and Athiyamaan's redemption through truth.
