Osaka is known for its dynamism, and you can enjoy the fruits of this energy in a couple of days. If you stay longer, use Osaka as a base to explore the surrounding Kansai region—Kyoto, Nara, and Kobe are each 30 minutes away by train. Osaka is also the most convenient jumping-off point for a trip to the mountainside monasteries of Koya-san, two hours away on the Nankai private rail line.
Twenty-four hours in Osaka will give you a chance to catch many of the city's major sights. Osaka-jo,Osaka's majestic castle, should be first on your list. Then head south to Tenno-ji Koen,a park that contains the Municipal Museum of Fine Art and its collection of classical Japanese art. Nearby Shitenno-ji,also known as Tenno-ji, is the oldest Buddhist temple in Japan. In the afternoon head to Den Den Town to browse through the gadget stores or to Yoroppa Mura and Amerika Mura for fashion. At the end of the day, Dotombori-dori is the place to go for dinner and nightlife.
With two full days in Osaka, you can cover all the city's major sights. To the above day-in-town suggestions, add Sumiyoshi Taisha,one of the three most famous shrines in Japan, Senri Expo Park and its museums, the Municipal Art Museum of Asian Ceramics in Naka-no-shima Koen, and the shops on Mido-suji. Plan to catch a performance at the National Bunraku Theater late in the afternoon. To wrap up your stay, instead of heading to Dotombori-dori after dark, go to central Osaka.