Japan has a reputation as an easy place to eat vegetarian. Tofu, vegetables, rice, seaweed — it looks straightforward on paper.
It is not, and the reason is a single ingredient.
Dashi is in almost everything, and on almost no menus
Dashi is the foundational stock of Japanese cooking. It is usually made with katsuobushi — dried, smoked, fermented skipjack tuna — often with kombu seaweed.
It is in miso soup. It is in most simmered vegetable dishes. It is in the dipping sauce for tempura and for cold soba. It is in the broth of most udon and ramen. It is in many dressings.
And it is essentially never listed, because to a Japanese kitchen dashi is not an ingredient. It is the water.
This is why a dish of simmered vegetables — visibly containing nothing but vegetables — is frequently not vegetarian.
The word that actually helps
精進料理 (shōjin ryōri) is Buddhist temple cuisine. It is vegan by construction: no meat, no fish, no dashi made from bonito, and traditionally no alliums either. Kombu dashi is used instead.
It is available near major temples, at some ryokan, and increasingly in dedicated restaurants in Kyoto and Tokyo. If you are going to learn one term, learn this one.
ベジタリアン (bejitarian) is understood but frequently interpreted as "no large pieces of meat." It is not a reliable signal on its own.
Dishes that are usually a reasonable starting point
- Zaru soba — cold buckwheat noodles served plain, with the dipping sauce separate, so you can ask before using it
- Inari sushi — rice in sweet fried tofu pouches
- Vegetable tempura — the batter is usually flour, egg and water; the dipping sauce is the thing to ask about
- Yasai itame — stir-fried vegetables, though the seasoning is worth checking
Note that "usually" is doing real work in every one of those. None of them is a guarantee.
The question worth asking
出汁は昆布ですか、鰹ですか。 Dashi wa kombu desu ka, katsuo desu ka? "Is the dashi kombu or bonito?"
This is a normal question that a kitchen can answer immediately, and it is far more useful than announcing a dietary category.
A note on strictness
If you are vegetarian by preference, Japan is very manageable. If you are vegetarian for religious or ethical reasons where trace bonito matters, treat temple cuisine and specialist restaurants as the plan rather than the fallback.
TableSage flags dashi and bonito on a scanned menu, along with the other things that never get printed. It will not tell you a dish is safe — recipes vary and the kitchen has the final word — but it will tell you what to ask.
More detail: Vegetarian at a Japanese restaurant and How to read a Japanese menu.
