Mutthananna, the village simpleton, is a poor orphan and a good musician who has a physically-challenged sister, Bhavani. Kiran Kumar a.k.a Diamond Kiran, Mutthu's lookalike, is a billionaire and a wanted thief and diamond smuggler. When Mutthu arrives in the city, he suddenly meets Kiran Kumar and was happy and shocked to see him. Kiran convinces Mutthu to stay with him like a brother. After a few days, Kiran tells Mutthu he has cancer and wants Mutthu to keep his businesses going by taking his place. Mutthu accepts his every order without knowing that he is a wanted thief. When Mutthu comes to know that he a thief, Kiran hits him and blackmails him to take his place--otherwise he will torture Mutthu's sister. Will Mutthu comes out of Kiran's deadly trap? How he will save his sister?