How Do You Eat Safely With Food Allergies in Japan?

You’re at a conveyor-belt sushi restaurant in Tokyo. The salmon nigiri looks simple — just fish on rice. But the soy sauce you’re about to pour on it is brewed from 50% wheat, the rice was seasoned with dashi (fish stock), and the imitation crab two plates over is bound with wheat starch. Three hidden allergens in what looks like the simplest meal in the world.

Japan’s three foundational ingredients — dashi (だし, bonito fish stock), shoyu (醤油, soy sauce containing wheat and soy), and miso (味噌, fermented soybean paste) — appear in nearly every dish and are invisible to diners. Restaurants have no legal obligation to disclose allergens. But Japan’s packaged-food labeling is among the world’s most detailed, convenience stores are your safest fallback, and allergy cards in Japanese get real results.

TL;DR: Soy sauce (醤油) contains wheat. Dashi (fish stock) hides in miso soup, omelets, simmered vegetables, and even some pickles. Restaurants don’t have to tell you any of this. Say “komugi arerugii” (小麦アレルギー) instead of “celiac” — staff recognize mandatory allergens. Konbini packaged food lists the 9 mandatory allergens. Carry a printed allergy card in Japanese.

Why Is Japan One of the Hardest Countries for Food Allergies?

Japan welcomed a record 42.7 million international visitors in 2025 (Japan National Tourism Organization), and the food is a top reason people visit. But three foundational ingredients make it one of the hardest countries for allergy management: dashi (bonito fish stock), shoyu (soy sauce containing both wheat and soy), and miso (fermented soybean paste). They appear in nearly every dish — and you’ll never see them on the plate.

According to the Annals of Allergy, Asthma & Immunology, 30% of food-allergic travelers experienced allergic reactions during trips abroad, with restaurants as the primary cause. In Japan, the risk is compounded by a dining culture where custom orders aren’t standard. A restaurant may politely decline your reservation if they can’t accommodate your allergy — that’s actually a sign of responsibility, not rudeness.

What Does Japan’s Allergen Labeling Law Actually Cover?

Japan mandates allergen labeling for 9 specific ingredients on packaged food, but restaurants have zero legal obligation to disclose anything. According to the Consumer Affairs Agency of Japan, the mandatory list covers egg, milk, wheat, buckwheat, peanut, shrimp, crab, walnuts (added 2023), and cashew nuts (added March 2025, transition period through March 2027). Soy and sesame, both mandatory in the US and EU, are only “recommended” in Japan.

One critical difference: Japan prohibits “may contain” (precautionary allergen labeling). If an allergen IS listed on a package, it’s definitely present above 10 ppm. But absence from the label doesn’t guarantee absence — it means below threshold or the manufacturer chose not to add a voluntary cross-contamination statement.

What Are the Most Dangerous Hidden Allergens in Japanese Food?

Dashi, soy sauce, and miso — Japan’s three invisible foundations — often work together in a single dish. A bowl of miso soup contains all three: katsuo-dashi (かつおだし, bonito fish stock) as the base, miso (味噌, fermented soybean paste) stirred in, and the whole thing built on a flavor profile anchored by soy sauce. That single bowl hits fish, soy, and wheat allergies simultaneously.

According to Pediatric Allergy and Immunology (Yoshisue et al., 2024), food allergy prevalence in Japan doubled from 0.47% to 1.03% between 2010 and 2019 — yet restaurant allergen disclosure hasn’t kept pace. The gap between Japan’s excellent packaged-food labeling and its nonexistent restaurant labeling is where allergic travelers get hurt.

Where Does Dashi Hide Beyond Miso Soup?

Dashi is Japan’s invisible backbone — the stock base that defines the cuisine. The default at most restaurants is katsuo-dashi (かつおだし), made from bonito (skipjack tuna) flakes, meaning it contains concentrated fish protein. If you have a fish allergy, these dishes will catch you off guard:

Safe alternatives exist: kombu-dashi (昆布だし, kelp only) and shiitake-dashi (椎茸だし, mushroom only) contain no fish. You’ll find these at shojin ryori (精進料理) Buddhist restaurants. Ask: “dashi wa sakana desu ka?” (だしは魚ですか? — “is the dashi fish-based?”).

Which Sauces and Seasonings Contain Hidden Wheat?

Standard Japanese soy sauce — koikuchi shoyu (濃口醤油) — is brewed from roughly 50% wheat, and it accounts for 80% of all soy sauce consumed in Japan. Every teriyaki glaze, ponzu dip, yakisoba sauce, tonkatsu sauce, and yakiniku marinade is soy sauce-based, which means virtually every brown sauce in Japan contains wheat.

Tamari (たまり醤油) is your alternative — traditionally brewed with little to no wheat, it’s a Chubu region specialty available at larger supermarkets like Life and Seijo Ishii. But check the label: some commercial brands add wheat. According to FARE, food allergies affect approximately 10% of US adults — many of whom travel to Japan without knowing soy sauce contains wheat. Bringing your own tamari bottle is the most reliable approach.

Which Japanese Dishes Are Usually Safe for Each Allergy?

No Japanese dish is guaranteed safe — cross-contamination is standard and many staff don’t fully grasp the concept (コンタミネーション, kontamineeshon). But knowing which base recipes avoid your allergens turns impossible meals into manageable ones. According to the Annals of Allergy, Asthma & Immunology, food allergy prevents 14% of allergic persons from traveling abroad entirely — you don’t have to be one of them.

How Do You Tell a Japanese Restaurant About Your Food Allergy?

Here’s the most important communication hack for Japan: say “komugi arerugii” (小麦アレルギー, wheat allergy), not “celiac” or “gluten-free.” Celiac disease prevalence in Japan is approximately 0.05% — among the lowest globally (Journal of Gastroenterology and Hepatology) — so the concept isn’t well known. But wheat (小麦, komugi) is one of Japan’s 9 mandatory label allergens, and staff are far more likely to recognize it.

Notify ryokans and kaiseki restaurants at booking time — these kitchens plan menus days in advance. Show your allergy information directly to the chef, not just the server — information sometimes gets lost in relay.

Should You Carry an Allergy Card or Use an App?

Both. Carry a printed allergy card in Japanese — the Tokyo Metropolitan Government publishes a free Food Allergy Communication Sheet with pictograms in multiple languages. Hand it to kitchen staff, not front-of-house servers. According to FARE, “travelers with food allergies should carry translated allergy cards and verify ingredients directly with kitchen staff, not front-of-house servers.”

The most reliable approach combines a physical allergy card with a way to verify the menu before you order. I built Menu Decoder for the scanning part — photograph a Japanese menu and it flags dishes based on your specific allergy profile, including hidden ingredients like dashi and soy sauce — but the card is equally important. Neither alone is enough. If you’re also traveling through Southeast Asia, see our guide to eating safely with food allergies in Thailand.

Which Types of Restaurants Are Safest in Japan?

Not all Japanese restaurants pose equal risk. According to FARE, more than 40% of children with food allergies have experienced anaphylaxis — choosing the right restaurant type is a first-line defense. Hotel restaurants and international chains have English-speaking staff and allergy protocols. Chain restaurants publish detailed allergen charts you can review before you even walk in.

Outside major cities, your options narrow significantly. In rural areas, konbini packaged food becomes essential — their mandatory allergen labeling works everywhere in Japan.

What Regional Specialties Should You Watch Out For?

Japanese cuisine changes dramatically by region, and so does your risk profile. The biggest trap is in Okinawa: jimami tofu (じーまーみ豆腐) is labeled “tofu” but is made entirely from peanuts, not soybeans. The name means “ground bean” in Okinawan dialect. Peanut flour is also sometimes blended with kinako (きなこ, roasted soybean flour) on mochi in Okinawa.

Frequently Asked Questions

Does Japanese soy sauce contain gluten, and can celiacs safely eat it?

Yes — standard Japanese soy sauce (koikuchi shoyu / 濃口醤油) is brewed from roughly 50% wheat and 50% soybeans. It’s in virtually every cooked dish, marinade, and dipping sauce in Japan. For celiac disease — which affects approximately 1.4% of the global population according to Clinical Gastroenterology and Hepatology — this makes Japan one of the hardest countries to navigate. Soy sauce fermentation does degrade some wheat proteins, which means the risk profile differs between IgE-mediated wheat allergy (where even degraded proteins can trigger reactions) and celiac disease (where the question is whether gluten peptides survive fermentation). Most celiac organizations still recommend avoiding standard soy sauce entirely. Your alternative is tamari (たまり醤油), traditionally brewed with little to no wheat — it’s a Chubu region specialty available at larger supermarkets like Life and Seijo Ishii. Check the label: some brands add wheat. Bringing your own bottle from home is the safest approach.

Can you eat safely at Japanese convenience stores (konbini) with food allergies?

Konbini (コンビニ) — 7-Eleven, Lawson, FamilyMart — are often your safest option in Japan. The Food Labeling Act requires all packaged processed food to list the 9 mandatory allergens (egg, milk, wheat, buckwheat, peanut, shrimp, crab, walnuts, and cashew nuts) if protein exceeds 10 ppm. Look for the allergen disclosure section (アレルギー表示, arerugii hyouji) on the back of every onigiri, bento, sandwich, and snack. The 21 “recommended” allergens, including soy, sesame, and various tree nuts, are widely labeled by major konbini brands even though it’s voluntary. The catch: fresh deli items like oden (おでん) from the hot counter and nikuman (肉まん, steamed buns) follow different rules and may not have full allergen information. Stick to factory-sealed packaged items for the highest certainty. The Payke app lets you scan barcodes on Japanese products to see ingredients in English.

How do you handle food allergies at a ryokan kaiseki dinner?

Notify the ryokan at booking time — not when you arrive, and definitely not at the table. Kaiseki (懐石料理) is a 7-12 course fixed menu prepared hours or days in advance. Chefs plan ingredients, presentations, and substitutions well ahead of service. Many ryokans will ask about allergies on their booking form, but if they don’t, email or call at least 3 days before arrival. Be specific: “komugi arerugii” (小麦アレルギー) is clearer than “gluten-free.” Send your allergy card in advance so the chef can review it. Some ryokans may decline your reservation if they cannot accommodate a severe allergy — this is a sign of responsibility, not rudeness. Cross-contamination is a real concern because fish-based dashi runs through the entire kitchen. If your allergy is to fish and the ryokan uses katsuo-dashi as their base, there may genuinely be no safe way to serve you.

Can you bring an EpiPen into Japan?

Yes. You can bring up to approximately one month’s supply of EpiPens (エピペン) into Japan without special import paperwork — carry your prescription and a doctor’s letter in English. EpiPen is the only epinephrine auto-injector available in Japan. You cannot buy one over the counter; getting a Japanese prescription requires a consultation with an allergist or dermatologist, and the process requires Japanese-language communication. If you use your EpiPen, call 119 — Japan’s emergency number — and say “kyuukyuusha wo onegai shimasu” (救急車をお願いします, “please send an ambulance”). Tell them “arerugii hannou” (アレルギー反応, “allergic reaction”) or “anafirashikii” (アナフィラキシー, “anaphylaxis”). Japan’s emergency response is fast and reliable in urban areas. Also note: some common medications like Adderall are completely illegal in Japan regardless of prescription — check import rules for all your medications before traveling.