Thevar Magan tells the story of Muthusamy (played by Kamal Haasan), a larger-than-life figure who returns to his village after a long time abroad. As he navigates the complexities of his family and community, Muthusamy must confront his own demons and reconcile his past with his present. The movie takes the audience on a journey of self-discovery, as Muthusamy's character evolves and grows, revealing the intricacies of human emotions.