People often ask me what they should expect before coming to Japan. It's hard to say, but if you don't speak Japanese, at first you'll be limited to communicating with Japanese people who can speak English. Be ready to meet these people:
The hardcore Japanese: These are people are Japanese inside and out, and are single-handedly responsible for keeping the traditional Japanese arts alive. They grow bonsai, give ikebana exhibitions and hold tea ceremonies in their homes. They speak textbook English, know more about English grammar than a native speaker and may have been abroad once or twice on holiday. They always put foreigners on a pedestal, so you'll enjoy being treated as king or queen, always given the best seat and receiving the most exotic food. These people will also be proud to show you off to their friends, so you'll get called on to attend weddings of people you don't know and lectures in Japanese that you can't understand. The hardcore Japanese give many gifts and are always out to impress you. You won't be disappointed. These people grow in clumps at culture centers and international events, serving as Japan's welcome committee for foreigners.
The biculturals: These people have lived abroad for a year or two and can speak some slang, maybe even do the high five. Outside, they appear almost "gaijin," with their casual English and easygoing manner. But inside are traditional Japanese values and deep bows. When they speak English they are free spirits, but when they speak Japanese they are conscious of their social status and their relationship to their superiors. They are happy living a double life -- being Japanese with an occasional jaunt into the gaijin world via the English language. The biculturals may be prone to imaginative ideas such as giving up the corporate life to raise cattle in Hokkaido. Despite their free spirit, they retain enough of their Japaneseness to still give you the seat in front of the "tokonoma."