Chitra (Nayantara), a medical student and her friends are working on a project about the human brain. She wants to investigate the curious case of Sanjay Ramaswamy (Suriya), a (former) notable Chennai based businessman, who is reported to have anterograde

Shah Rukh Khan and Sharad Kapoor are the leaders of the two rival gangs. Aishwarya Rai is Shah Rukh Khan’s twin sister. Shah Rukh is in love with Priya Gill. Chandrachur Singh is Sharad Kapoor’s younger brother who studies in a catering college in Bombay.