Cast: Vijay as Vetrimaaran, Vetri, and Maaran, Samantha as Tara, Kajal Aggarwal as Anu Pallavi
Vijay starrer Mersal was a runaway hit at the box office continuing the successful streak of Vijay and Atlee combination. Mersal which had Kajal, Samantha and Nithya Menon in the lead roles has Vijay playing triple roles. Coming to the story of Mersal, to put it in a simple way it is about how the twin brothers of a good man taking revenge on the villain who killed him.
Vijay is introduced as Maaran, a doctor and he goes to Europe for a conference and on the other hand another magician Vetri played by Vijay is also introduced there. Kajal falls with Vetri in Europe and after returning from Europe, Maaran falls in love with Tara played by Samantha. In Europe Zachariah gets killed by Vetri but the police arrest Maaran claiming him as the murderer.
Going into the flashback, Vijay is introduced as Vetri Maaran, a brave and good man who goes to any extent for the welfare of his people. After the occurrence of an accident in a festival ceremony, Vetrimaaran plans to build a hospital and he happens to meet Doctor Daniel Arockiyaraj.
Vetrimaaran's wife played by Nithya Menen joins the hospital for delivery. Daniel and Zachariah in a plan to grab more money from Vettrimaaran perform a cesarian operation though she could deliver the child normally. In the process Nithya Menen gets killed because of overdosage of aesthetics. Vetrimaaran who comes to know the truth tries to kill Daniel but in the process, he gets killed. How the children Vetri and Maaran take the revenge on Daniel and Zachariah for killing their parents must be seen in the movie.