Unnidathil Ennai Koduthen

Selvam and Bhaskar steal a Ganesh idol from a temple for a client who has just moved into a new house. The theft triggers a frantic chase as locals pursue them through the town. They flee and take shelter in a house, where Radha, a maid, and the owner's three children cross paths with them.

While on the run, the thieves are locked in a room by Radha and the children for three days. Through this confinement, Radha realizes they are not wholly bad, and Selvam begins to fall for her. A quiet bond forms between them during this period.

On the day the owners return, Bhaskar steals Radha's handbag containing her diary. Selvam reads the diary and learns Radha is Vishwanathan's daughter, a revelation that complicates her standing in the family. This knowledge foreshadows the conflicts to come.

Vishwanathan's second wife and sister dislike Radha and push for her removal. He plans to marry Radha to his brother-in-law Sanjay, but Sanjay asks for three months to decide.

Radha waits for Sanjay's decision over the next three months as the marriage plan lingers. She faces pressure from relatives while pondering her future. The waiting period also gives Selvam space to reflect.

Inspired by Radha's advice, Selvam resolves to reform and live more responsibly. He begins taking up honest work to pay for Radha's hostel stay and consciously tries to suppress his feelings for her.

Selvam helps Radha connect with music director Gangai Amaran and facilitates an opportunity for her to sing. He also helps repair the director's car, earning goodwill that boosts Radha's chances.

Radha's talent leads to rapid success, making her wealthy. She moves into a bungalow with Selvam and Bhaskar, starting a new life together.

During an interview, Radha avoids naming her father. Vishwanathan then reveals that he is the father, and his wife accepts Radha as her daughter after seeing her wealth. They come to stay at Radha's bungalow.

Vishwanathan's wife resents Selvam and Bhaskar living with them and pushes for Radha to marry Sanjay. To complicate matters, she and her sister stage a drama accusing Selvam of stealing Radha's money, forcing the two men to leave.

Radha returns to the villa and discovers Selvam's diary in his room, understanding his deep love for her. The revelation deepens her feelings and commitment to him.

At an award ceremony, Radha declares that Selvam was the reason for her success and confesses her love. Selvam appears on stage after being seen on TV, and a flashback shows Radha's prior confession to Sanjay and Vishwanathan. The film ends with Selvam and Radha leaving hand in hand.