Osaka is the most beautiful city in Japan. I like it better than Tokyo. It is modern meets the history.
Play: there are several historical sites to see in Osaka. Go there early in the morning since most of them close early in the afternoon. See them slowly, and sit down to watch the Sakurai if you can. In the night, there are places to go for family time as well as personal time. Go to the night market if you wanna see the real local Japan. There are Karaoke in Japan, they offer young ladies and guys to entertain you, but please be careful with that.
Living: Living cost in Osaka is average, but living space is really crowded. Hotel room is generally smaller than 15 square meters. Hotels in Japan is not enjoyable place, just go back there when you need sleep.
Transportation: Take train and bus. In downtown, walking is the best option. Taxis are expensive and required pre-order. taxi driver are most friendly people in the world, but most them can only speak Japanese.
Eating: If you experience real Japan, Eat in some local places. Order shushi and sashimi. Don't order then if you are afraid of raw food. Please know that Japanese food serve in a light size, order 2 dishes if necessary.
Shopping: European and American brands are really expensive in Japan. Go to local night market to find all the interesting special item you like for a low price.