Ke Tumi Nandini is the story of a young girl Nandini who wants to make her own rules in life. The only daughter of a tea estate owner she has grown up under the strict guidance of her parents. However, she wants to be free as a bird now.

Nandini manages to break free from her native place Sikkim and arrives in Kolkata. She enters the Chatterjee family in disguise and manages to stay with them. Soon she gets adjusted with the family and wins everybody's love and affection. She even wins a special friend: the grandfather of the family.

Nandini gets emotionally attached to the kids of the family and is admired by the young and handsome grandson of the family Sayan. The story begins from here on...