Jana movie begins in a remote village Thamaraipadi, where Ajith renders service for village. Sneha, daughter of Radharavi, comes from Mumbai for her vacation. She falls in love with Ajith and returns to Mumbai with his photograph. She eventually comes to know about his past life. Ajith goes all-out to wage a battle against gangsters and criminals.
He incurs the wrath of an antisocial Siddiq, who kills his mother Sri Vidya and his brother Manoj K Jayan. This forces him to reach Tamilnadu with his father Raghuvaran, to lead a peaceful life. Troubles do not end for him there. The villain and his associates reach the village and pick up a fight with him.