Of cause when you go to Japan, you want to eat Japanese food. They are so good and much cheaper in Japan (usually). But if you really need to eat wester food, they are there as well.
You cannot find huge meals like in the USA in Japan. That might be one of the reasons people in Japan in general are smaller than the people in the US. In addition, people rely on the public transportation and do o drive as much in the cities in Japan. That contribute to more expertise.