(; ) is a designated city in the Kansai region of Japan. It is the capital city of Osaka Prefecture and the largest component of the Keihanshin Metropolitan Area, the second largest metropolitan area in Japan and among the largest in the world with over 19 million inhabitants. Situated at the mouth of the Yodo River on Osaka Bay, Osaka is the second largest city by the daytime population after Tokyo's 23 wards and the third largest city by the nighttime population after Tokyo's 23 special wards and Yokohama in Japan, serving as a major economic hub.