Happy movie is all about Bunny (Allu Arjun) who is a happy-go-lucky guy. This pizza delivery boy lives life for the moment. He comes across Madhumathi (Genelia)who is a medico, who is pursuing studies against heavy odds as her father is an obscurantist of sorts who thinks a woman’s rightful place is in the kitchen. Bunny and Madhumathi don’t hit it off initially. They are at each other’s throat.
But fate brings them together, and the situation becomes so sensitive that Bunny ends up tying the knot with her. Yet Madhumathi and Bunny don't love each other.But Bunny being orphan understands the value of education. So he sets out get her complete her studies against heavy odds. Does he manage to do that and do the young couple begin to understand each other? Well, these are questions for which you can find an answer in the end.