Durai(Arjun), a do-gooder, runs an orphanage for the elderly and in his spare time, eliminates dreaded rowdies off the streets. His mother(Sujatha) considers him a rowdy because of his violent life and lives separately with her daughter. But Anjali(Mallika Kapoor), a camerawoman with a TV channel, sees his good side and falls for him. Durai is the thorn in the side of policeman Eswarapandi(Prakashraj), who is itching to see him behind bars but is unable to pin anything on him since nobody is willing to testify against Durai. Naachiyaar, the ex-CM who was jailed by the current administration, is hellbent on coming back to power and Eswarapandi, who is in Nachiyaar's good books, sees an opportunity to get rid of Durai.

Vaathiyaar takes too long to get to a story and for most of the running time, moves along aimlessly. We know that the ex-CM is going to be the villain but the film doesn't establish any link between him and Arjun until very late into the proceedings. So until then, the film proceeds in episodic fashion, with Arjun going up against assorted rowdies who have no effect on the big picture and having repeated run-ins with Prakashraj. Even a potentially serious issue, like the water pollution because of the factory, which is capable of driving an entire movie, is dealt with in a lame fashion and is never brought up again.

Arjun's orphanage for elderly women and his caring for them brings back memories of his appalam factory in Gentleman. The setting adds some fun to the otherwise-tepid romance with the older women trying to help Mallika in her attempts to woo Arjun. But one feels the situation hasn't been exploited fully and a few throwaway jokes are all one gets. Having the older women try to sabotage Mallika's attempts(a la Gentleman) or allotting more screen time to their attempts to help Mallika(as in Rojaavanam ) might have made things more interesting. Vadivelu and 'Venniraadai' Moorthy join in also but don't make things any funnier.

As expected, there is a flashback that explains how Arjun became the rowdy that he is today and why his mother has disowned him. It also explains the title of the movie since Arjun was a teacher but the profession makes absolutely no difference since he is still a superman, thrashing up the wrongdoers. Its only the environment that changes since he now beats up misbehaving teachers in a school ground! Once the movie gets back to the present, there is a nice little twist about one of the characters but its effect is diluted since the movie has lost us by then.

Arjun goes in for a hairstyle change but little other than that has changed. He is enthusiastic in the stunt sequences as always. Mallika Kapoor tags along, pining for Arjun and paving the way for duets. Prakashraj is his usual self. Vadivelu continues his 2 recent trends for his comedy tracks - he is led to think that Mallika is in love with him and manages to land up in situations where he is at the receiving end of some blows. Unfortunately, neither track is funny.