Tokyo is the capital of Japan. Kawasaki, Sagamihara, and Yokohama these metropolitan areas are included in administrative boundaries of Tokyo, making it most populous area of the world. So Tokyo is standing at number 1 in most populated areas of the world, containing 37,200,000 people in his lap. There is slightly decline seen in the population rate of the Tokyo according to UN, but it will still remain most populated city of the world till 2030 with its 37 million dwellers.