As the geography and climate are very different in Japan, staple foods are also very varied from one region to another. Of course, the common base will often be rice (rice, round and usually with vinegar, and vermicelli noodles). They adapt depending on what region you are in. The noodles are usually wheat or buckwheat based sushi.
Relatively few fresh or raw vegetables are eaten in restaurants. In restaurants, they are usually served marinated in brine, as an accompaniment to rice: turnips, yellow radishes,… But at home with the family, they are eaten a lot, and have always been. There are many dishes based on potatoes, sweet potatoes and legumes, radishes, mushrooms, white cabbage and Chinese cabbage, to name a few main ingredients. Of course we must not forget soy and seaweed, which are very common in Japanese cuisine. Starting with the tofu and wakame seaweed found in the miso soup.