As one might expect, the main demographic of Osaka is Japanese. The foreign community is made up predominantly of Koreans and Chinese, but there is a noticeable international community of English teachers and businessmen from foreign companies that have offices in Japan. It's not hard to find English speakers in the center of the city upon moving to Osaka.
People from Osaka are known for being some of the most forthright and boisterous in Japan. They love their food and drink and the local Osaka dialect is colorful and expressive, something that has made the area famous for producing popular comedians. At times in contrast to other parts of Japan, especially neighboring Kyoto, people can seem more casual and relaxed in their attitudes.
Osaka has four distinct seasons, five if you include the rainy season in spring. Temperatures in winter are mild and dry and the city rarely sees any snow.
The summers are very humid and air conditioning is a must if you want to sleep well at night, with an average night time temperature of 25°C in July and August, 10°C below the average daytime temperature of 35°C.
Japan likes to celebrate each season with festivals and different kinds of food, so you can expect to be outside enjoying life with the locals no matter what the weather.
There are some companies that offer help to renters and they are probably your best bet if you want to avoid as much hassle as possible after your move to Osaka. Fees for moving in can be expensive in Japan, with a deposit, insurance, guarantor and 'key money' (a gift to the landlord, usually one or two months' rent) to add to the agents' fees. Accommodation without key money is becoming more common so it's worth looking around to get the best deal.
Don't expect to get a lot for your rent money though, space is at a premium and single apartments that consist of a room with a kitchen and separate bathroom are the norm. Entertaining at home isn't a big part of Japanese culture and working hours can be long, which means small apartments are all that's needed to sleep, wash and relax for a short time each day.
Don't be put off by the imposing blocks of apartments all over Osaka, the locals are used to living in the same way and are considerate about noise.