It's a story about lucky love
and how love stays strong. The title is formed from the
first alphabets of the lead pair's name in the film: Jagan
and Jamuna. Jay Jay is a remake of the Hollywood film
Serendipity, starring John Cusack and Kate Beckinsale.
Jagan -Madhavan and Jamuna -Amoga meet in a shopping mall in
Chennai. They like each other and spend a day chatting in
the coffee shop. Jamuna, a believer in destiny, writes down
her address and telephone number on a Rs.100 note and makes
the payment at the cafe declaring that if the note comes
back to Jagan then it means that he was destined to meet
her. He tries hard to trace the note but in vain. Jamuna
goes back to Kolkata. Meanwhile Pooja -Pooja, who was
rescued by Madhavan from some thugs, has a crush on him.
Finally Jagan manages to get Jamuna address on the eve of
her wedding and unites with her.