Kasautii Zindagii Kay is the story of Anurag and Prerna. It is the story of the trials and tribulations their love faces.

Anurag is the handsome, soft-spoken son of a rich, loving father - Moloy Basu. Moloy is a good-natured, large-hearted man. His wife Mohini, on the other hand, is arrogant and manipulative.

Prerna is the daughter of Moloy's best friend, Rajesh. She is a girl of traditional values, but modern aspirations.

Moloy and Rajesh's friendship has withstood the test of time and difference in social status. They dream about getting their children, Anurag and Prerna, married to each other. The children resist the idea at first, but later fall in love with each other!

Circumstances, however, force Anurag to agree when his mother arranges to get him married to Komolika.

Prerna is shattered and decides to take revenge on Anurag. A remorseful Anurag does everything he can to help her - to the extent that he even aids her in her quest for revenge.