Doo is well knit tale, the story begins with Vasanth (Sanjay) who works in the sub registrar office. He lives with his mom (urvashi) and hangs out with his friends (jeeva, jegan). His life takes a turn when he meets his school friend Swapna (nakshatra), a software professional.

In no time, they fall in love. However, as they get to know each other, things begin to change and they split.The story takes a turn with the arrival of Anu (sangeetha), a journalist and she takes a special position in Sanjay's life. However, both Sanjay and Swapna are unable to come over each other's absence.