Soy allergy, understood in Japanese.

Soy sauce · 醤油 (shoyu)

Standard Japanese soy sauce (koikuchi shoyu) is brewed with wheat in roughly equal parts to soybeans, so the table soy sauce served with sushi, sashimi, and dumplings contains gluten and is unsafe for celiacs unless it is specifically tamari or labeled gluten-free.

Tamari is usually wheat-free and the standard gluten-free swap, but some tamari brands add small amounts of wheat, so the label must still be checked. Wheat-allergic (not just celiac) travelers should treat standard shoyu as a wheat exposure.

Imitation crab (kanikama) · カニカマ / 蒲鉾

In Japan, stick-type imitation crab (kanikama) used in sushi and salads looks like plain seafood but commonly hides wheat in its starch along with egg white, soy, and real crab extract, so check the label of each brand before eating.

Ingredients vary by brand and product type. The wheat plus egg-white combination is typical of stick-type kanikama used for sushi, but some products are explicitly egg-free and some flake or salad types omit wheat. Crab extract and soy are near-universal, and the surimi base is fish. Always read the per-product allergen label.

Shabu-shabu sesame dipping sauce (goma dare) · ごまだれ / 胡麻だれ

At a shabu-shabu hot pot, one of the two standard dipping sauces (goma dare) is built on ground sesame paste, so choosing the wrong bowl delivers a heavy sesame dose with no visible seeds to warn you.

Goma dare is made from neri goma (sesame paste), so the sesame is fully ground in and not visible as seeds. Shabu-shabu is conventionally served with two dipping sauces, sesame (goma dare) and citrus ponzu; the sesame one is the hazard. The sauce also commonly contains soy sauce and dashi.

Japanese curry roux · カレールウ

Most Japanese supermarket curry roux blocks are built on a wheat-flour roux and commonly contain milk solids and soybean, so a standard bowl of Japanese curry is a hidden source of gluten, dairy, and soy unless you confirm an allergen-free brand.

The wheat roux is universal in standard curry; milk and soy vary by brand. Best-selling blocks like House Vermont Curry declare milk, wheat, and soybeans. Dedicated vegan and allergen-free roux products exist, so milk- or soy-allergic travelers must read each specific package allergen statement.

Miso soup · 味噌汁

A bowl of miso soup that looks like only tofu and seaweed is almost always built on fish-based dashi (bonito or dried sardine), so it contains fish unless explicitly made with kombu or shiitake stock.

Standard restaurant and home miso soup uses katsuobushi (bonito) or niboshi (dried sardine) dashi and contains fish even when none is visible. The fish-free exception is dashi made purely from kombu (kelp) or dried shiitake, common in Buddhist shojin-ryori but uncommon by default. Ask whether the dashi is fish-based rather than assuming a plain-looking bowl is safe.