Osaka was traditionally considered Japan's economic hub. By the Kofun period (300–538) it had developed into an important regional port, and in the 7th and 8th centuries it served briefly as the imperial capital. Osaka continued to flourish during the Edo period (1603–1867) and became known as a center of Japanese culture. Following the Meiji Restoration, Osaka greatly expanded in size and underwent rapid industrialization. In 1889, Osaka was officially established as a municipality.

Osaka is a major financial center of Japan. It is home to the Osaka Securities Exchange as well as the multinational electronics corporations Panasonic and Sharp. Famous landmarks in Osaka include Osaka Castle - which played a pivotal role in the Siege of Osaka and was featured in the 1980 American television mini-series Shogun - and Shitennō-ji - the oldest Buddhist temple in Japan.

Japan is officially divided into 47 prefectures and traditionally into eight regions. Approximately two-thirds of the country's terrain is mountainous and heavily forested, and less than one-eighth of land is suitable for agriculture. Consequently, Japan is among the most densely populated and urbanized countries in the world, with over 90% of its population living in urban areas. The largest of these is the metropolitan area centered on the capital city of Tokyo, which is the most populous in the world and home to more than 38 million people. Japan itself is the world's eleventh most populous country with a population of 126.2 million, of which 97.8% are ethnically Japanese.