Mammootty begins life as Kunjumon, the son of a dhaba-owner (Innocent), and the lucky charm of a local businessman played by Devan. When Devan starts a five-star hotel he allows Innocent to continue plying his trade on the adjacent plot of land, which was owned by him, but occupied by Innocent for over 10 years. Circumstances force Mammootty to go to Kozhikode, where he starts his own dhaba and grows up to be a tough man (a la bhai) with a heart of gold, and comes to be known as Gulan ( or the Jack in a pack of cards)
Trouble starts when the manager of the five star hotel and his sons plot to get rid of Devan and acquire the hotel for themselves. They also decide to throw Innocent out of the land he occupies, thus ridding the hotel of an eyesore at its entrance. Innocent then plays his trump (Thuruppu) in the form of his son, Gulan, and how the baddies are overcome forms the rest of the story.
If you take a wafer thin storyline and flesh it out with dollops of comedy and action, you will wind up with an entertainer which will pull in the masses. When the viewer comes out of the theatre, he will say "Great movie", but if you ask him about it a week later, he wont even remember the story! That is the essence of Thurupu Gulan, and the director has certainly dealt an ace on the movie-going public with this effort. Watch it for pure entertainment, but dont expect it to tickle your intellect!