In Ooty, Kathir [Jai Sampath] is an ambitious young man with training in hotel management who dreams of owning a glamourous 5-star hotel. His brother, Saravanan Jiiva, works in a startup abroad and shares a life with his live-in partner, Neetu Aishwarya Dutta. Their other brother, Ravi Srikanth, teaches music, while their sister Varshini is pregnant and often vents about her workaholic husband, Santhosh. Radhika Samyuktha Karthik is Ravi’s wife who tries to rekindle their romance and even attempts to lose weight, though Ravi’s interest has faded. Shruthi is their daughter, bringing a light touch to family life.
Though Kathir appears successful, his girlfriend dumps him for a newer flame, “Shining star” Rohan, and Kathir resigns from his job to return to Ooty. He keeps the truth from most of the family, telling only Varshini because she is close to him. Meanwhile, a Colonel owns the land Kathir wants to develop, and the Colonel’s family holds the key to the land.
Abi [Amritha Aiyer] is Kathir’s close friend who also secretly admires him. At the Colonel’s 25th wedding anniversary, Kathir hatches a plan to marry the Colonel’s daughter, Diya [Malavika Sharma], to secure the land. Both Diya’s parents consent to the alliance, and they even plan to arrange the weddings of Saravanan and Kathir in a joint celebration. Saravanan, initially hesitant, still clings to a lie he has kept from the family.
Meanwhile, Ravi becomes infatuated with Sara [Raiza Wilson] and they share a one-night stand, after which Sara distance herself, leaving Ravi heartbroken. Kathir then tasks Saravanan with picking up Diya from the airport as he heads off to Abi’s birthday. Abi’s birthday surprise unfolds when Kathir discovers Abi’s secret wishes in her diary and helps to grant them, the last one being a kiss with her favorite person, which ends up revealing the fragility of Abi’s trust as Kathir suddenly tells Abi that he will secure the land for them—shattering Abi’s heart.
As the days pass, Saravanan and Diya grow closer and fall in love, which weighs on Saravanan’s conscience. Kathir reveals a childhood memory: a schoolgirl once proposed to him, but he rejected her to preserve a friendship. Knowing this, Saravanan begins to pull away from Diya. Abi, meanwhile, runs away, and Kathir realizes he has fallen for her. He tracks Abi only to find her engaged to Arvind, which prevents him from making a proposal.
The family learns about Neetu, so Saravanan asks that a new bride be found for him to avoid complicating Diya’s situation. The wedding planners arrange a bride for Saravanan, who turns out to be Sara. Ravi makes frantic efforts to stop the wedding, but nothing goes as planned. Radhika grows more suspicious of Ravi’s behavior.
On the engagement day, Kathir proposes to Abi, who treats this as a joke. Kathir promises to win Abi’s heart within 30 days. He also secretly tweaks the wedding card for Diya’s event without anyone noticing. Varshini notices Saravanan and Diya together and challenges Saravanan, who insists that Kathir’s happiness matters and vows to win Diya’s heart within 30 days. Ravi, too, vows to derail Saravanan’s marriage to Sara within the same 30-day window.
Meanwhile, Saravanan plans a birthday surprise for Diya featuring her favorite Panipuri and credits Kathir for the idea. The family gathers for a photoshoot, and Ravi provokes Sara’s grandmother, resulting in a rift that threatens Saravanan’s engagement. Saravanan urges the family to move forward with Kathir’s marriage plan. Kathir confesses his love for Abi to Varshini and goes as far as kidnapping Arvind and leaving him at a pub, where Abi witnesses some troubling behavior; she confronts Kathir, accusing him of treating Abi as a second option and ending their friendship.
Saravanan later receives a visa to Australia and learns from Sara that Ravi leaked photos of him with Neetu to scuttle the wedding. Enraged, Saravanan confronts Ravi and discovers Kathir’s true feelings; he then unexpectedly proposes to Diya at her home, unaware of Kathir’s earlier breakup. Ravi eventually confesses his affair with Sara and apologizes, but Radhika leaves the family with Shruthi.
Saravanan publicly denies loving Diya to his parents and brings Neetu home as Kathir pushes him about his breakup. Diya, heartbroken, contemplates a move to the United States. Abi discovers a wedding card bearing Kathir’s name and realizes he always loved her, accepting his love in return. The film reaches a warm, familial note as the family members reunite at Shruthi’s school dance program; Shruthi mocks the chief guest, Rohan, a plan Diya had helped instill to heal Saravanan’s heart.
Realizing the depth of his feelings, Saravanan races to stop Diya at the airport. A staged delivery-pain ruse by Varshini buys time to talk to the pilot—who is actually her husband, Santhosh—allowing the lovers to find their moment. In the end, the two brothers are married to the partners they love, and the family gathers to celebrate Varshini’s baby naming ceremony, closing the story on a note of reconciliation and happiness.
