Ranbir Kapoor, Deepika Padukone, Karan Johar and Ayan Mukerji graced the first look and trailer launch of their film 'Yeh Jawaani Hai Deewani' in Mumbai. Ranbir and Deepika smartly answered media queries about their chemistry in the film in context to their stint as a couple few years back. A very interesting watch; don't miss!