Manmadhan movie revoles around Two brothers look a same (Silambarasan) who is the younger one is a play boy who enjoys his leisure time partying with girls, while the older Simbu is a calm type. But he has another face. A psychotic.Problems starts when the girls, who parties with the younger Simbu are murdered one by one.Meanwhile a lady doctor, Mandhira Bedi has been called to treat the older Simbu who has a mental disorder. She founds out that he is the killer whom the police are looking for. This brings the twist in the story. Why he is the killing...