Happy-go-lucky Prem (Ranbir Kapoor) has never had a hard day of work in his life -- he's too busy enjoying himself and trying to make other people smile. But when he falls for Jenny (Katrina Kaif), Prem realizes he must get serious about his future if he hopes to win her heart. Soon he's putting in long hours at a shop and trying to convince the girl of his dreams that her upcoming wedding, to another guy, is a bad idea.