Despite the fact that this is his first film, he does not overreact/overact in any scene; he is so full of real-life that he appears pretentious; every line he utters, the subtle emotions his face displays, and every demeanour of him makes you grow fonder of him as the drama progresses; he is that believable and exceptional.
Vijay Sethupathi plays a very eccentric character in the film, and he nails it. There's a scene where he gives food to a Sadhu, and the entire scene is so cathartic, that your eyes will be filled with tears with a smile on your face, it makes you go through emotions that you yearn to experience all the time, it's that powerful, and Vijay Sethupathi's performance in that scene is so magnificent that you'll be wishing he grabs all the awards.