Harikrishnan (Mohanlal) is an immigrant in Mumbai, who like many thousands of immigrants is busy struggling to make ends meet. He shares a room with a group of Malayali guys, who have their own personal problems and difficulties. The film begins with Harikrishnan witnessing the murder of a journalist, and being asked by police to appear at an identification parade, which he does. Hari and his friends stay at a room in Kamathipura, which also homes the largest red lighted area in India. He accidentally meets Kiran (Geetha), a Telugu girl in the brothel, for whom he develops feelings. In a short attempt to make money, Hari and friends start making local hooch, which is supplied by Manikandan (Jagadish), their friend, who is also a taxi driver. One of the friends, Shekhar (Shankar), falls in love with the sister of Mani, without the knowledge of anyone else.On a fine morning, Mudaliar, the Tamilian don, who was ruling the street is shot dead by Abbas Ali (Rami Reddy), his own henchman, who has shifted his loyalty to Amar Bakia (Mahesh Anand), another cold blooded don. With the death of Mudaliar, Amar Bakia becomes the undisputed don of the city, and Abbas Ali, his lieutenant. Abbas, after coming to know about the small scale smuggling activities of Hari and gang, threatens him and asks him to come and meet him on the day of Vinayak Chathurthi and pay him a large amount as fine. In midst of the celebration, Hari enters the house of Abbas Ali and shoots him down, inviting the enmity of Amar Bakhia. Chottu (Cochin Haneefa), a local goon belonging to Bakhia gang, attacks Hari and beats him up mercilessly. He is saved by the lady owner of a brothel and she along with Kiran takes care of him. With this incident Hari becomes the local leader and within a short span Chottu and others join his gang. Hari, thus becomes Hari Anna, who also becomes a negotiator in land disputes, financial matters and local business stiffs. Amar Bakhia is now in serious efforts to end the gang of Hari, but Hari on the other hand is getting stronger day by day. Shekhar, now gets a job at a Marwari business group and ditches the sister of Mani. She, who is pregnant by then, commits suicide. Mani, shocked by this incident, is unaware of Shekar's involvement with his sister and indirect cause of her suicide. Hari decides to marry Kiran and with the help of his friends plan to start up a new life outside Mumbai. Amar Bakhia orchestrates attacks on Hari and his gang, leaving many of Hari's friends dead. Hari plots revenge and executes those responsible including Amar, and prepares to escape with Kiran. Meanwhile, Mani gets a letter written by his sister to Hari, which makes him believe that it's Hari who is responsible for the death of his sister. Mani informs police about Hari's plan to leave Mumbai by the night. While parting, Hari informs Mani about Shekhar and expresses regret for not being able to save her. On realizing the truth, Mani reveals the ambush plans and asks Hari to escape before police reaches the spot. But it is too late by then, as police surround him and shoot him down.