Kaathala Kathala (1998)

Ramalingam (Kamal Haasan) and Sundaralingam (Prabhu Deva) are simpletons who are always in search of ways to earn a quick buck. Sundaralingam is an artist with good talent, while Ramalingam is the business brain who brings in money, mostly by fraudulent means. They fall in love - Sundaralingam with Janaki (Rambha) and Ramalingam with Sundari (Soundarya). Both are students of art. Janaki's father, played by the music director M. S. Viswanathan, rejects Sundaralingam. Sundari convinces Janaki to write letters falsifying Sundaralingam's rise to fame and big money, eventually lying that Janaki and Sundaralingam now has a son, hoping to win over the parents with sentiment. Janaki's dad, worried that his grandson might be brought up poorly, arrives at a mansion that has been set up to look like Sundaralingam's new property, along with her mom (Srividya). Meanwhile, Sundari's dad (Moulee) also makes an unexpected stop there to check on his daughter. A small misunderstanding during introductions and progressively bigger lies to cover the initial lies lead to a side-splitting laugh riot. How those four eventually overcome their problems and find happiness forms the rest of the story.