Muthu (Kamal Haasan) is an 18-year-old simpleton who works in a small village. He is sexually harassed by his landlord's sister, a widow. Unable to bear it any longer, Muthu goes to Madras. However, he is again harassed in a similar way by people whom he meets. He finds work at a hotel as a room boy where he meets Maragadham (Srividya), a prostitute. He then rescues her once from a raid. After he saves her, she develops a soft spot towards him. He lives in Maragadham's house as a servant but later is thrown away from her home. In the end Muthu gets affected by an STD and is shown in a hospital being treated by a doctor and eventually dies.