If your only experience with Japanese food is eating at the so-called “Japanese restaurants” that have become incredibly popular throughout the world over the years, you could be forgiven for thinking that the latter is a faithful recreation of how Japanese cuisine is consumed in Japan.
In reality, however, Japanese tend to segregate types of dishes to the extent where each could be considered a cuisine unto itself; restaurants generally specialize in specific types of food (e.g., tempura restaurants for tempura, udon restaurants for udon, and so forth). Accordingly, it is somewhat unusual to find dishes with distinctly different characteristics offered at the same establishment (you generally won’t find sushi served at a sukiyaki restaurant, for example). This is perhaps because Japanese see each variety of their traditional food as being as different from one another as washoku as a whole is from Mexican or Moroccan, each with its own pedigree and heritage that rightly deserves to stand on its own.
Far from being a homogenous genre of national cuisine, washoku offers any number of distinct varieties of dishes that have evolved from local, regional and foreign influences, with some only being eaten at specific times of the year out of consideration for the season.