Pithamagan whirls around four characters. Chithan (Vikram) who is orphaned at a young age, devoid of all human contacts lives on his animal instincts and ekes out a living as a graveyard caretaker.
He seems to exhibit behaviour consistent with autism spectrum disorders. Gomathy (Sangeetha), a petty ganja seller, who pities Chithan’s condition, gets him a job at the ganja fields of the main villain. Sakthi (Surya), the conman, cons Manju (Laila), a polytechnic student but does not get away with it.
Sakthi meets Chithan in jail and takes pity on him and...