Three Bottles, Three Very Different Jobs

You're standing in the condiment aisle of a Japanese grocery store, staring at three bottles that look surprisingly similar. One is a soft squeeze bottle with a red cap. The other two are brown, glossy, and labeled with characters you may or may not read. Which one do you grab?

Here's the thing: Japanese mayonnaise (Kewpie), tonkatsu sauce (Bull-Dog), and okonomiyaki sauce (Otafuku) are built on completely different flavor philosophies and ingredient logic. They're not interchangeable, and each one does something the others simply can't.

What might surprise you is how far each of these bottles can travel beyond its namesake dish. From steak marinades to stir-fry glazes, these three condiments are showing up in kitchens and on social media in ways that would have seemed unlikely even a few years ago. This guide is for anyone curious about Japanese condiments, whether you've been cooking Japanese food for decades or you're just getting started.

Japanese Mayonnaise: Why Kewpie Tastes Like Nothing Else

If you've ever tasted Kewpie mayo side by side with a standard American brand, you already know: they're not the same product. The difference starts with the eggs. Kewpie uses only egg yolks, not whole eggs. This produces a richer, more custard-like texture and a deeper golden color. It also means a higher fat content per serving, which translates to a creamier mouthfeel that coats food differently.

Then there's the vinegar. American mayo relies on distilled white vinegar, which gives it a sharp, sometimes aggressive tang. Kewpie swaps that for rice vinegar (or sometimes apple vinegar), creating a gentler, slightly sweet acidity. The result is a mayo that enhances other flavors instead of competing with them.

The real secret weapon is umami. Kewpie contains MSG or yeast extract, an ingredient entirely absent from standard American mayo. This is what gives Kewpie its almost addictive depth: that savory quality you can't quite place but can't stop eating. Even the packaging plays a role. Kewpie's signature soft squeeze bottle is specifically designed to minimize oxidation, keeping the mayo fresher longer. It's functional engineering, not just a cute design choice.

Kewpie has been Japan's flagship mayo since 1925, and the brand celebrated its 100th anniversary in March 2025 with a global campaign spanning 14 countries, including a Times Square billboard in New York. It holds the top market share in Japan by value. American demand is surging too: Kewpie went viral in 2021 when Emily Mariko's salmon rice bowl took over social media, and in May 2025 the company opened a new production facility in Tennessee to keep up with US orders. This is no longer a niche import.

Beyond the Spicy Tuna Roll: Creative Ways to Use Kewpie Mayo

Kewpie's egg yolk richness and built-in umami make it remarkably versatile. Here are some uses that have been trending across food blogs and social media through 2025 and 2026:

• Steak marinade: Spread a thin layer on steak before searing. The yolk fat and MSG create a golden, umami-rich crust.
• Grilled corn topping: Slather on corn in place of butter for a Japanese-inspired take on elote.
• Grilled cheese spread: Use it on the outside of the bread instead of butter for a richer, crispier crust.
• Ramen broth enricher: Stir a spoonful into your bowl for instant creaminess and depth.
• Quick dipping sauce base: Mix with a splash of soy sauce or sriracha for a fast gyoza or tempura dip.

Tonkatsu Sauce: Japan's Meiji-Era Answer to Worcestershire

Tonkatsu sauce has a fascinating origin story. During the Meiji period (1868–1912), Japan was rapidly absorbing Western culinary influences. English Worcestershire sauce arrived on Japanese shores, but its thin consistency and sharp flavor didn't quite pair with local fried foods. Japanese producers adapted it, thickening the sauce and sweetening it to complement breaded pork cutlets (tonkatsu) and other fried dishes. A new condiment category was born.

The most iconic brand in this space is Bull-Dog Sauce Co., founded in 1902 (originally as Misawaya Yoko). Bull-Dog's tonkatsu sauce became a household staple by the 1950s and remains the dominant brand in the Kanto (Tokyo) region. If you've eaten tonkatsu at a restaurant in Tokyo, you've almost certainly tasted Bull-Dog.

To understand where tonkatsu sauce fits, it helps to know the Japanese brown sauce hierarchy. The word "sauce" (ソース) in Japanese almost always refers to a Worcestershire-base brown sauce, and the family breaks down by thickness: Worcestershire (thin) → Chuno (medium) → Tonkatsu/Noko (thick). Tonkatsu sauce sits at the thick end, with a fruit-and-spice base built on apple, tomato, prune, and onion. It's slightly thinner and spicier than okonomiyaki sauce, with a clean, savory-sweet finish. Its primary role is as a pour-over sauce for tonkatsu, korokke, and other deep-fried foods.

Tonkatsu Sauce Far Beyond the Cutlet

Once you start thinking of tonkatsu sauce as a fruit-and-spice condiment rather than a single-dish topping, its uses multiply fast:

• BBQ sauce substitute: Brush onto grilled chicken, ribs, or pork. The fruit-and-spice base behaves similarly to a smoky American BBQ glaze.
• Burger condiment: Spread on a brioche bun in place of ketchup for a savory-sweet upgrade.
• Sandwich spread: A natural fit for katsu sando, but it works just as well on deli-style sandwiches.
• Quick marinade base: Mix with grated ginger and garlic for a fast pork or chicken thigh marinade.

Practical tip: Tonkatsu sauce works as a 1:1 substitute for okonomiyaki sauce in most recipes. If you only have one bottle, you can make it work.

Okonomiyaki Sauce: The Dashi-Powered Sauce With a Hiroshima Soul

Otafuku Foods, founded in 1922 in Hiroshima, is the brand virtually synonymous with okonomiyaki sauce in Japan. When Japanese consumers picture okonomiyaki sauce, they picture Otafuku's bottle. The brand carries a strong regional identity tied to Hiroshima and Osaka, the two cities where okonomiyaki culture runs deepest.

So what actually separates okonomiyaki sauce from tonkatsu sauce? They're both in the thick (noko) sauce family and share a similar fruit base. But okonomiyaki sauce adds something tonkatsu sauce doesn't: dashi-style stocks. Kombu, shiitake mushroom extract, sometimes oyster extract or kelp powder. These ingredients give okonomiyaki sauce a broth-like, layered umami base that fundamentally changes its character.

The flavor profile is slightly thicker and sweeter than tonkatsu sauce, with almost no spiciness. It's gentler and more purely fruity, with a deep savory undertone from the dashi. Its primary job is as the essential finishing sauce for okonomiyaki (Japanese savory pancakes), applied in a zigzag pattern and paired with Kewpie mayo. That combination of sweet, savory, and creamy is one of the most satisfying flavor experiences in Japanese street food.

Okonomiyaki Sauce Beyond the Pancake

Okonomiyaki sauce's sweetness and dashi complexity make it surprisingly adaptable:

• Yakisoba seasoning: Toss with stir-fried noodles, cabbage, and pork for an instant yakisoba sauce. This is one of its most natural secondary uses.
• Stir-fry glaze: Add a tablespoon to any vegetable or protein stir-fry in the last 60 seconds of cooking for a glossy, sweet-savory finish.
• Dipping sauce for fried snacks: Serve alongside karaage, tempura, or even french fries as a sweeter, more complex alternative to ketchup.
• Noodle bowl drizzle: Use as a finishing sauce over udon or soba in place of a heavier tare.

Substitution note: Okonomiyaki sauce can stand in for tonkatsu sauce, but the dashi notes will add extra complexity to the dish. Worth knowing before you swap.

Quick Reference: Which Sauce Should You Reach For?

Here's a side-by-side breakdown to keep things simple:

• Kewpie Mayo: Rich, creamy, umami-forward. Egg yolk base, rice vinegar, MSG. Reach for it when you want fat, creaminess, and depth. Best non-traditional uses: steak marinade, grilled cheese spread, ramen enricher.
• Tonkatsu Sauce (Bull-Dog): Fruit-and-spice, slightly spicy, medium-thick. Reach for it when you want a savory-sweet sauce with a little kick. Best non-traditional uses: BBQ glaze, burger spread, quick marinade.
• Okonomiyaki Sauce (Otafuku): Sweeter, thicker, dashi-layered, no heat. Reach for it when you want complex umami sweetness without spice. Best non-traditional uses: yakisoba seasoning, stir-fry glaze, fried snack dip.

Substitution cheat sheet: Tonkatsu and okonomiyaki sauce are interchangeable in most recipes, though you'll notice flavor differences. Neither substitutes for Kewpie mayo, which operates in a completely different category.

Our honest recommendation? Stock all three. These aren't single-use specialty items. They're the foundation of a Japanese condiment pantry that will change the way you cook every week.

Find All Three at Tomato Japanese Grocery

We carry Kewpie mayo, Bull-Dog tonkatsu sauce, and Otafuku okonomiyaki sauce as part of a selection we've been building and refining for over 20 years here in Marietta, GA. Every product on our shelves is chosen with care, because we believe the right ingredients are the first step toward an authentic experience.

You can shop with us in store with local pickup in Marietta, or we ship nationwide via UPS for customers across the country. Browse our full condiment and pantry section to start building your Japanese kitchen at home.

For our family, these bottles aren't just condiments. They're a connection to the food, the culture, and the traditions we grew up with. We're here to help you discover that same connection, one recipe at a time.