LKG tells the story of Lalgudi Karupiah Gandhi, a 29-year-old councillor, who is witty and street-smart. He is popular in his ward and belongs to the ruling party. Even a recommendation letter from the Chief Minister's office demanding a seat is just tossed away by a popular school in his area, but LKG makes the principal allot him five seats. He is not all that powerful but knows the tricks of the trade.
LKG doesn't want to wait long to make it big in politics. He wants it to happen now. His main influence is his father, a failed politician. Real-life politician Nanjil Sampath is brilliantly cast in the role and he doesn't have to do much; just showing up on screen at the perfect time brings out the laughs. Gandhi is not inspired by his father, but carefully constructs his life to not end up like his dad.
So, LKG goes knocking on the doors of a corporate company, which would devise a strategy to help him gain traction not just in his ward but throughout the state. There he meets Sarala Munusmay, the heroine (Priya Anandh).
Meanwhile, the CM dies in the hospital and the ruling party is divided into two. One section supports deputy CM Bojappan (Ramkumar) for the next CM and another troop is with Ramraj Pandian (JK Rithesh). Sounds familiar? of course, it is.
Now, LKG has to use the opportunity to his own personal gains. He plays the game of thrones and how!