How to Treat Vegetarians and Vegans
When a person living as a vegetarian / vegan considers traveling in Japan, how much can he/she enjoy Japan?
In Japan, since there had basically been no custom of eating meat of animals for more than 1000 years until the Edo period (From 17th century), cooking methods to deliciously eat foodstuffs without using meat, and soybean processed foods etc have been developed well. In other words, vegan or vegetarian travelers can enjoy traditional Japanese food without being patient and compromising on tastes, by choosing right places.
As Japanese cuisine made from such ingredients centering on "vegetables" and "tofu", there is a "Shojin Ryori (vegetarian feast)" made according to the Buddhist way of thinking, which is also recommended for vegetarians and vegans. Shojin Ryori is a human body-friendly meal, which does not contain fish and meat, as well as foods with strong smell called “Gokun” (garlic, Chinese chive, Japanese leek, onion, and chive) that are supposed to hinder Buddhist training.
Although this is "Japanese food" which can be provided with only vegetables and tofu used, it is necessary to be cautious about "soup stock." Many Japanese dishes use bonito, kombu, shiitake mushrooms, etc. as a typical soup stock material. Among them, bonito is fish. In other words, when vegan and vegetarian people eat Japanese dishes, you need to pay attention to materials of soup stock. As for the "Shojin Ryori", as temples prohibit any killing, you can be assured that everything is made from ingredients derived from plants, including soup stock.
Like this, it is an advantageous point that a full-scale traditional Japanese cuisine can be offered to even vegetarians. However, as there are not so many vegetarians and vegans in Japan, understanding about and measures for them have not been sufficiently advanced, as seen in various modern Japanese foods, such as ramen and curry rice.
In urban areas, supermarkets specialized in vegetarian and vegan food, and ramen stores offering menu in accordance with rules of vegans and vegetarians can be found. It's a good idea to check the access from your lodging in advance. On the other hand, outside the urban areas, there are many people who have never met vegetarians/vegans. Therefore, it may be difficult that an intent of question is well understood. For example, they would not be sure why you ask about materials of soup stock, or why you need soy milk instead of cow milk? However, Japanese people concerned with tourism intend to respect customs and eating habits around the world. Even if they are not understood easily, it does not mean the rejection. Japanese people will do as much as they can.
In other words, if you are aiming to enjoy Japanese food, preliminary study is very important. By searching available restaurants, etc. in advance, you should be able to most enjoy Japanese food.