Bunty(Aditya Roy Kapoor) loves his girlfriend Tanya(Sudeepa Singh) but runs a mile whenever she mentions marriage. His phobia with matrimony stems from his parents Kishen(Akshay Kumar) and Mala's(Aishwarya Rai) acrimonious marriage. But now Bunty is in a fix. Tanya's grandfather, Professor Anthony Gonsalves, as given him an ultimatum - get married to Tanya or stop seeing her. Bunty knows that unless he does something fast, his dreams of living happily ever after with Tanya will bite the dust.
As Bunty's surprise party for his parent's 35th wedding anniversary deteriorates into yet another explosive fight between Kishen and Mala; he decides to turn back the clock and rewrite Kishen and Mala's destiny and alter their disastrous arranged marriage into a romantic affair of the hearts.
And how does he do that? By stealing the professor's time machine to travel back in time! To a time when Kishen and Mala were not married...To a time when Kishen's father Rai Bahadur and Mala's mother, Boli Devi were sworn enemies...To a time when his father Kishen was certified nerd, bullied merciless by his father...To a time when his tomboyish mother couldn't stand the sight of his father and took great pleasure in ragging him silly...
Bunty has his work cut out for him. He has to transform his father from a wimp into an eligible bachelor and his mother from a tomboy into the epitome of feminine grace. Then he has to attempt an impossible task - make them fall in love with each other.
And finally - he has to make his grandparents agree to their love marriage! Because until and unless he does this, his own love story with Tanya will never have a happy ending...