Unnal Mudiyum Thambi

A mischievous, high-society youth who transforms into a committed social reformer. After a wake-up moment when he ignores a blind beggar, he shifts toward helping others and vows to serve society. He leads the village to confront liquor shops, inspires the Amaidhi Puratchi Iyyakam movement, and falls for Lalithakamalam, whose secular views strengthen his resolve.

A secular-minded woman whose bold actions inspire Udhayamoorthi. She slaps a thug in a theatre and stands up for the underprivileged, reinforcing the film's message that equality and justice are universal. Her love for Udhayamoorthi motivates the couple's joint effort to reform the village.

A devout Carnatic musician and stern patriarch who trains Udhayamoorthi and disapproves of his son’s worldly compassion. He embodies tradition, discipline, and high standards, often clashing with his son’s humanitarian aims. In the end, he recognizes his son’s mission and unites the family.

Initially brought as Pillai’s disciple to counter Udhayamoorthi, Charukesi demonstrates musical skill and ambition. He acts as a rival who pushes Udhayamoorthi to stay true to his ideals, and later aligns with the reform movement. His presence adds tension and then mutual respect within the reform narrative.

Udhayamoorthi’s sister-in-law who softens harsh judgment and provides emotional support. She experiences the family’s transformation alongside the village and mourns earlier misgivings while championing the reform movement. Her empathy helps bridge personal and communal healing.

A turbulent politician who embodies the old order and later acknowledges the village’s reform. His presence frames the reform as a political win for the people, validating the villagers’ efforts. He serves as a catalyst for government attention and broader social change.

A local liquor seller who embodies the forces resisting Udhayamoorthi’s reforms. His shops become targets of the movement, illustrating the clash between personal livelihood and communal wellbeing. His interactions with the village highlight the economic stakes of reform.