Sheeba, a young girl caught in the struggles of her traditional family, is desperate to escape an arranged marriage imposed against her will by her parents. Her innate desire for independence drives her to plot an escape, hoping to find someone who can help her stand up to her father, Baby. Thinking she might find an ally in Peter, a local goon, she tries to woo him while planning her escape, but her plans quickly spiral out of control. Everything backfires, and she finds herself with no choice but to return home, feeling frustrated and trapped.
Meanwhile, Suku, a passionate and somewhat hopeless romantic who owns a local graphic design shop, is dealing with his own issues. He harbors a deep dislike for his father, Sujithkumar, mainly because of his old-fashioned name, which he wishes to change. Suku’s close friends include Paachan, a respectful and caring friend who looks up to him, and Kunjaayi, who runs an electrical repair shop. There's also Suma, his neighbor and a nurse, who secretly harbors feelings for Suku. However, he dismisses her affection, claiming she is like a sister to him, much to her disappointment.
One day, Suku and Paachan travel to Coimbatore to buy a new digital printer. Their trip takes a dangerous turn when, staying overnight at a lodge, a thief attempts to steal Suku’s motorcycle. The friends pursue him, and in the chaos, Suku inadvertently kills the thief. Frightened, they hurry back to their village, trying to avoid police detection. Suku is overwhelmed with guilt and fear of imprisonment, so Paachan introduces him to his uncle, Thanku, a small-time criminal well-versed in law and police procedures. Thanku advises Suku to feign insanity as a defense, telling him to acquire a mental health certificate to use in court. Suku ends up admitted to a mental health facility for ten days to obtain the necessary certificate.
While Suku is in the hospital, his mother and her friends passing by unknowingly see him there, fueling village gossip that Suku has gone insane. Once released, Suku learns from Paachan that the police have closed the case, mistaking the incident as a hit-and-run, and that he has evaded arrest. But upon returning home, he faces hostility from everyone, including his own family, who start treating him as mentally ill despite his increasing frustration.
At the same time, Sheeba, determined to be free of her oppressive family and their shackles, begins to pursue Kunjaayi, who decides to visit her at her home during her pre-wedding celebrations. He convinces Suku to join him, and what begins as a simple visit quickly turns chaotic when Sheeba uses the opportunity to elope once more. Suku finds himself caught in the middle, trying to protect her from her furious parents. To avoid further conflict, Suku takes Sheeba to his house, believing Kunjaayi was behind the plan. However, he soon discovers that Sheeba was the mastermind of her own elopement, and Kunjaayi had no part in it.
Despite her staying at his home for the night, things take a humorous turn when her presence is revealed in the morning, and Sheeba boldly claims she is Suku's girlfriend who has run away from her step-parents, who want to marry her forcibly to claim her inheritance. Her story is accepted by his family, much to everyone's surprise.
As Sheeba tries to find her footing, Suku, Paachan, Kunjaayi, and Suma attempt various schemes to separate her from Suku, but all fail. They uncover that Sheeba is an orphan with step-parents who aim to seize her inheritance by marrying her off against her wishes. She dreams of completing her education and living freely, and she resists being pulled back into her family's plans. Sheeba’s resilience inspires Suku, who, despite his feelings, makes several awkward attempts to impress her, only to be rebuffed. Her disdain finally pushes Suku to a mental breakdown.
The situation escalates when Baby and some armed goons come to take Sheeba away, but Suku, overwhelmed with emotion and rage, fights them off violently, revealing a far more intense side of himself. Ultimately, Suku confesses everything to his family and vows to support Sheeba by enrolling her in a women’s hostel, ensuring she'll have the space to pursue her dreams and her education legally.
With Sheeba now confined to her hostel, she finally experiences the life she always yearned for, taking significant steps toward independence. She thanks Suku for his unwavering support and apologizes for the troubles she caused him. In a heartfelt moment, Suku privately confesses his love, only to be gently rejected. Nevertheless, he finds solace in the realization that he has been able to help her and, for the first time, recognizes Suma's love for him. He then bravely confesses his feelings to her, and she joyfully accepts, bringing a new beginning for both.
Through all these tumultuous events, Thanku remains a pivotal character, helping Suku navigate the complexities of his accidental crime and moral dilemmas, eventually guiding him toward a path of redemption and self-belief. The story ultimately centers on themes of love, resilience, family conflicts, and the pursuit of personal freedom, wrapped in humorous and emotional moments that highlight the characters’ growth and change.
