Today, 55% of the world's population lives in urban areas, a proportion that is expected to increase to 68% by 2050 according to the United Nations. But as more of the world's population gravitates towards our urban centres, how do our city leaders, planners and architects stay ahead and make our cities better places to live and work? In Leading Cities Tokyo, Mariko Oi looks at one of Asia's most vibrant cities, exploring innovations in robotics, transportation, farming, housing and leisure. Show less