Santosh Subramaniam

Subramaniam, a wealthy businessman, arranges Santosh's engagement to Rajeshwari to secure the family's future. He believes marriage will keep Santosh aligned with the business and his guidance. Santosh is shocked by the arranged match but feels powerless to object.

Santosh meets Hasini, a college student with a playful, carefree attitude, and is instantly drawn to her. He begins a tentative romance, keeping it secret from his father. The budding relationship becomes the central conflict as Santosh weighs independence against family duty.

Subramaniam learns of Santosh's love and explodes with fury, insisting Hasini is not the right match. He orders Santosh to bring Hasini to their home and keep her for a week so she can win his approval. Santosh reluctantly agrees, hoping the visit will change his father's mind.

Hasini lies to her father Govindan that she is going on a college trip and travels to Santosh's home instead. She enters a new social environment where she must interact with Santosh's family and adapt to their expectations. Her deception creates initial tension within the family.

Hasini begins to build bridges with Santosh's mother and sisters, gradually winning their sympathy. She reveals to them Santosh's hidden habits, such as drinking, late-night outings, and plans to take a bank loan to start his own company. The family starts rethinking their views as she exposes the real man behind the façade.

Overwhelmed by the tension, Hasini decides to leave before the week is up and apologizes to everyone. She admits she is not the one who can fit into this traditional family. Santosh watches anxiously but stays quiet, unable to stop her departure.

An intense argument erupts between Santosh and Subramaniam, during which Santosh laments losing small pleasures because of his father's overprotectiveness. Subramaniam recognizes his fault, apologizes, and vows to be more considerate of his family's sacrifices. The moment marks a turning point in their relationship.

Santosh apologizes to Rajeshwari for the complications, and she gently explains to Ramamoorthy that she can find a better groom than Santosh. Rajeshwari's willingness to renegotiate her match indicates a shift in the wedding plans.

Subramaniam goes to Hasini to apologize for the earlier demands and lies. Hasini explains that Govindan is angry with her for lying, and she vows to obey her father's wishes for now. The tension between Hasini's family and Santosh's world remains unresolved.

Govindan distrusts Santosh because he has seen him drink with friends. Subramaniam proposes sending Santosh to Govindan's home for a week to test his character. The plan leads to a series of comic incidents between Govindan and Santosh.

After numerous humorous clashes with Govindan, he finally relents and agrees to the wedding between Santosh and Hasini. The family gradually accepts the match as Santosh shows commitment to reform.

With Govindan's approval secured, Subramaniam arranges the Hasini-Santosh wedding. The family reconciles its differences and embraces the new arrangement, bringing the story to a close.