Diya (earlier titled (Karu) opens with the heated argument between the parents of Krishna (Naga Shourya) and Thulasi (Sai Pallavi) in a hospital. The parents come to know that their respective son and daughter are in a serious relationship and the girl (who is just out of school?) is pregnant. After few minutes, both the families decide to conduct the wedding after five years on condition that they should concentrate on their studies and for that Thulasi has to abort the child.
Five years later, the lovers are happily married but Thulasi (now a doctor) has changed as she is living with the guilt of killing her child in womb and keeps updating a diary in the name of her daughter Diya!! Meanwhile, Krishna’s dad, Thulasi’s mom, uncle and the doctor who aborted the child dies in freak accidents. Thulasi realises that it is her unborn daughter who is behind these murders and her next target is Krishna. Can Thulasi save her husband from the spirit of Diya?The story focuses on Diya, an aborted child who is now 5-year-old ( Baby Veronica) who wants to take revenge and her deep love for her mother.