Osaka is a city in the Kansai region of Japan's main island of Honshu, a designated city under the Local Autonomy Law, the capital city of Osaka Prefecture and also the biggest part of Keihanshin area, which is represented by three major cities of Japan, Kyoto, Osaka and Kobe. Located at the mouth of the Yodo River on Osaka Bay, Osaka is the third largest city by population after Tokyo (special wards) and Yokohama.