Sridhar Vasudevan(Madhavan) is just one among the thousands of middle class men for whom life has settled into a routine. He is married to Vatsala(Sangeetha), has two children and works in a bank. A principled man, he is irked by the corruption that has crept into all walks of life. Things come to a boil when a tea-stall owner charges 2 Rupees more for a cool drink and that makes Sridhar embark on a crusade to correct the issues that he sees.

What separates the protagonist in Evano Oruvan from the heroes in those other commercial films(note that Madhavan here is a protagonist; Kamal, Vijayakanth and Vikram were heroes) is the lack of premeditation. Madhavan is frustrated by society and takes action but he doesn't have a plan in mind. The fact that his problems are realistic isn't surprising. What is new is that his responses to them are also realistic. He wants to change society but doesn't know exactly how. So his actions are born out of frustration and that makes him far easier to identify with.

The initial collage of scenes from Madhavan's life gives us a snapshot of his daily grind; the monotonous rut his life has fallen into. Only a few incidents that irk him(the issue with the water lorry, the school donation, the bending of rules at work) are actually illustrated but that quick rundown of his life helps us understand that he must have had many similar situations in the past, where his rigid stance and firm adherence to his own principles led to problems(Sangeetha mentions this in one of their conversations too). So when he finally snaps for a small issue at the teakkadai, we understand that it is not just because of that particular incident. The issues have been building up and that incident was just the last straw.

Though realistic and down-to-earth, the movie essentially follows the same narrative track as other movies with the 'man vs society' theme - Madhavan goes on a rampage after he reaches breaking point, unknowingly becomes a hero and is chased by the police. Madhavan's transformation into a kind of vigilante is short but understandable. His initial experiences give him the impression that resorting to violence does get him justice and so he gradually starts tackling bigger problems.

Unlike other films where the heroes go after men responsible for propagating the issue, Madhavan here has no set agenda. He doesn't go after anything in particular and corrects issues he sees on his way. For a while, this works. The things he encounters are natural and we are with him during his acts. But after a certain point, the director becomes over-ambitious. It becomes harder to believe the things Madhavan simply stumbles upon and so the events themselves fail to have an impact. The incident at the hospital and his stumbling on a drug operation are unconvincing and cinematic. Thankfully, the movie rediscovers its touch in the climax which is suitably low-key and manages to have an impact.

Madhavan plays a regular, middle-class hero just perfectly. He brings out very well his frustration at the way the system works and is sincere and convincing. His basic demeanor doesn't change once he turns vigilante and that is what keeps the movie grounded in reality even after the situations turn a little cinematic. And that is what makes even his grand monologue not sound over-the-top. Sangeetha is good as the housewife who just wants a better life and is frustrated when her husband's principled stand comes in the way. She is very natural when complaining to him or shouting at her kids. Seeman's strained dialog delivery and limited expressions seem a bit odd initially. But he does suit the role of the police officer who is torn between his duty and recognition of what Madhavan is going through.