Aisi Deewangi (Thenmerku Paruvakaatru) is a story of Set in the background of Theni, the story is about Murugaiyan, a Gothard. He has a loving mother, Veerai, who is a widow. She tries hard to raise Murugan but she has a lot of love for her. Meanwhile, there is a gang that attacks the villagers at night and steals their goats. Murugan, along with his group, manages to capture one of the members in an attack and discovers that it is a girl. His name is Pechi (Vasundhara Chietra), and his family steals goats for his livelihood. While Murugan develops feelings for her, Pechi’s family is considered quite dangerous. Veerayi realizes this and asks Murugan to marry the girl he likes. He refuses to obey her wish. However, complications arise between them. An old woman in her house asks Veerai to marry her son to the girl he loves. A widow tells how her husband was killed by that old woman. Her husband was killed by a group of thieves. The head of the gang is none other than the father of the girl his son loves.