Osaka, with a population of 2.5 million, is Japan's third largest and second most important city. It has been the economic powerhouse of the Kansai region for many centuries. Osaka was formerly known as Naniwa. Before the Nara Period, when the capital used to be moved with the reign of each new emperor, Naniwa was once Japan's capital city, the first one ever known. In the 16th century, Toyotomi Hideyoshi chose Osaka as the location for his castle, and the city may have become Japan's capital if Tokugawa Ieyasu had not terminated the Toyotomi lineage after Hideyoshi's death and moved his government to distant Edo (Tokyo).

Osaka Castle (Osakajo) construction started in 1583 on the former site of the Ishiyama Honganji Temple, which had been destroyed by Oda Nobunaga thirteen years earlier. Toyotomi Hideyoshi intended the castle to become the center of a new, unified Japan under Toyotomi rule. However, a few years after Hideyoshi's death in 1615, Tokugawa troops attacked and destroyed the castle and terminated the Toyotomi lineage. Osaka Castle was rebuilt by Tokugawa Hidetada in the 1620s, but its main castle tower was struck by lightening in 1665 and burnt down. It was not until 1931 that the present ferro-concrete reconstruction of the castle was built. Major repair works gave the castle new glamour in 1997. Inside the castle is a museum that documents Toyotomi Hideyoshi's life and the history of the castle.

Minami (South) is one of Osaka's two major city centers. Minami is Osaka's most popular entertainment and shopping district, located around Namba Station. Attractions include the Shinsaibashi Shopping Arcade, Amerikamura ("America Village"), Nipponbashi Den-Den Town (shopping area for discount electronics), Dogusujiya (shopping area for non edible restaurant supplies) and the colorful Dotonbori entertainment district.