Panchamirtham's script is based on the popular kids' TV series 'Mayavi Maareesan'. The film travels back and forth between two different periods to deliver a novel theme.

At Ravana's abode, there is a heated argument between Ravana (Prakashraj) and his brother Mareesan (Jayaram) when Ravana asks Maareesan to go to Sri Rama's ashram, disguised as a deer so that Seetha can be abducted. Maareesan refuses to take part in this dastardly plot to abduct Seetha. So Idumba (Raju Easwaran) and Ravana threaten Maareesan that his (Maareesan's) lover (Samiksha) will come to harm unless he complies. Finally, Maareesan agrees to Ravana's plan, preferring to get killed by the Almighty's holy arrow. When hit by the arrow, Maareesan transforms Idumba into an anklet and wears it on his leg, then happily takes the form of a rocky structure.

Years roll by. Cut to the present. Rajaram (Nasser) owns a tea factory. Seetha (Charanya Mohan) is a cook working there and Sri Rama (Arvind Akash) is the dietician. Sri Rama and Seetha like each other. Rajaram's distant relatives (M.S. Bhaskar and Mayilsamy) plan to steal the huge property. They engage Pandi (Karunas) and Muthu (Kanja Karuppu) to kill Seetha and accomplish the same. After several futile attempts, Pandi and Muthu push her from a mountain top. She falls exactly on the rocky structure of Maareesan, who regains his original human form; at that moment, his anklet slips from his leg and falls into the runnel (mountain stream); a fish swallows the anklet; a fisherman Manickam (again Nasser) catches the same fish in his net. When he cuts it open, Idumba springs from the anklet and promises to help Manickam. Both of them set out to win over his half-brother Rajaram and to get a share in their vast ancestral property.

Maareesan helps Seetha and protects her off from her relatives' threats and potential dangers. Again, both Maareesan and Idumba meet and are reminded of their old enmity. Their clashes continue. Who wins in the end? Do Seetha and Sri Rama unite? Do Manickam and Rajaram get even? After a comic string of events, all ends well in Panchamirtham.

The maiden effort of producers Abhirami Ramanathan and Nallammmai Ramanathan, Panchamirtham is produced under the Abhirami Mega Mall banner. With a clear view of creating it exclusively for kids and the young at heart, the producers have chosen a richly imaginative theme. Without much use of computer graphics, the required effects are achieved. Director Raju Easwaran's knack in creating the characters and connecting them through a sequence of events is praiseworthy. He has also used experienced actors such as Nasser (dual role), Prakashraj and Jayaram in fitting roles. Charanya Mohan and Arvind Akash (of Chennai-600028 fame) have performed well. Though Arvind Akash's role in the movie is that of a charming lover-boy, he shows promise, of becoming a perfect hero material, capable of doing a vriety of roles. Sundar C. Babu's music, particularly the song with Nasser's dance is good. Debutante Pramod Verma's camerawork is commendable.