Nearly five decades ago, a popular Tamil weekly published a serial called THUPPARIYUM SAMBU (Sleuthing Sambu) written by Devan, a humorist comparable to P.G.Wodehouse in creating immortal comic characters. This was an instant success because the hero, Sambu was a uniquely entertaining "sleuth" who established rapport with the entire Tamil reading public with his "exploits" which unearthed many peculiar crimes which were "solved" mostly by accident when Sambu stumbled on the clues.
A client arrives making an advance payment of a cheque for Rs.1,000/- to Sambu, declaring that he has some very important transactions in a few banks and he would like to have Sambu's presence outside the Bank each time to protect him from a rowdy by name Ratnam. The story comes out that the so-called client of Sambu was himself encashing a series of fraudulent cheques from the banks and avoiding his partner, Ratnam in the process. Whether the main criminal is caught and whether Sambu gets credit for that is to be watched in `VEMBUVIN MAMA PILLAI'.