If there's one onigiri flavor that has become an icon of Japanese convenience stores and home kitchens alike, it's Tuna Mayo Onigiri (ツナマヨおにぎり). Filled with a creamy mixture of tuna and Japanese mayonnaise, wrapped in fluffy rice, and often finished with crisp nori seaweed, this simple rice ball is a favorite among children and adults alike.

Originally inspired by Western-style tuna salad, Tuna Mayo Onigiri has become one of Japan's best-selling onigiri varieties. Its creamy, savory filling pairs perfectly with lightly salted Japanese rice, making it an ideal breakfast, lunch, picnic snack, or quick meal.

Easy to prepare and wonderfully portable, Tuna Mayo Onigiri is proof that a handful of everyday ingredients can create something truly satisfying.

What is Tuna Mayo Onigiri?

Tuna Mayo Onigiri is a Japanese rice ball filled with a mixture of canned tuna and Japanese mayonnaise. The filling is placed in the center of warm, seasoned short-grain rice, shaped into a triangle, round, or oval, and wrapped with a strip or full sheet of nori.

It is one of the most popular onigiri flavors sold in Japanese convenience stores because of its creamy texture, mild flavor, and satisfying richness.

Whether enjoyed at home or on the go, Tuna Mayo Onigiri is a classic example of Japanese comfort food.

Preparation Time

  • Prep Time: 15 minutes
  • Cook Time: 20 minutes
  • Total Time: 35 minutes
  • Servings: 6 onigiri

Ingredients

For the Rice

  • 3 cups cooked Japanese short-grain rice
  • ½ teaspoon salt
  • Bowl of water for wetting hands

For the Tuna Mayo Filling

  • 1 can (140–150 g) tuna, drained
  • 3 tablespoons Japanese mayonnaise
  • 1 teaspoon soy sauce
  • ½ teaspoon sesame oil (optional)
  • Freshly ground black pepper, to taste

For Wrapping

  • 3 sheets nori, cut in half
  • Toasted sesame seeds (optional)

Instructions

Step 1: Cook the Rice

Prepare Japanese short-grain rice according to the package instructions.

Allow it to cool slightly until warm enough to handle while remaining soft and sticky.

Step 2: Make the Filling

In a bowl, combine the drained tuna, Japanese mayonnaise, soy sauce, sesame oil, and black pepper.

Mix until creamy and evenly combined.

Step 3: Prepare Your Hands

Lightly wet your hands with water.

Sprinkle a little salt onto your palms to prevent sticking and to season the rice.

Step 4: Shape the Onigiri

Place a handful of warm rice in one hand.

Make a small indentation in the center.

Add about 1 tablespoon of the tuna mayo filling.

Cover with a little more rice.

Gently shape into a triangle by pressing lightly while rotating the rice ball between your hands.

Avoid pressing too firmly, as this can make the rice dense.

Step 5: Wrap and Garnish

Wrap each onigiri with a strip or half-sheet of nori.

Sprinkle with toasted sesame seeds if desired.

Serve immediately or pack for lunch.

Cooking Tips

  • Use freshly cooked Japanese short-grain rice for the best texture and shape.
  • Drain the tuna thoroughly to keep the filling from becoming watery.
  • Japanese mayonnaise provides a richer, slightly tangy flavor than regular mayonnaise.
  • Wet, salted hands help prevent sticking and add subtle seasoning.
  • Shape the rice gently to keep the onigiri light and tender.
  • Add the nori just before eating if you prefer it crisp.

Delicious Variations

Spicy Tuna Mayo Onigiri

Mix chili sauce or Japanese rayu into the tuna filling for extra heat.

Tuna Corn Onigiri

Add sweet corn kernels for a touch of natural sweetness and crunch.

Tuna Cheese Onigiri

Mix shredded cheddar or mozzarella into the filling for a creamy twist.

Avocado Tuna Onigiri

Combine diced avocado with the tuna mixture for a fresh, buttery flavor.

Wasabi Tuna Onigiri

Blend a small amount of wasabi into the mayonnaise for a spicy Japanese-style version.

Furikake Onigiri

Coat the outside of the rice ball with your favorite furikake seasoning instead of using nori.

What to Serve with Tuna Mayo Onigiri

  • Miso Soup
  • Japanese Pickles (Tsukemono)
  • Edamame
  • Seaweed Salad
  • Tamagoyaki (Japanese Rolled Omelet)
  • Karaage (Japanese Fried Chicken)
  • Green Tea
  • Fresh Fruit

Storage

Wrap each onigiri tightly in plastic wrap.

Refrigerate for up to 1 day.

For the best texture, enjoy the same day they are made.

Avoid freezing onigiri with mayonnaise-based fillings, as the texture may change after thawing.

Nutritional Information (Approximate per Onigiri)

  • Calories: 220 kcal
  • Protein: 8 g
  • Carbohydrates: 29 g
  • Fat: 8 g
  • Fiber: 1 g
  • Sodium: 280 mg

Frequently Asked Questions

Can I use regular mayonnaise?

Yes, but Japanese mayonnaise gives the filling its signature rich, slightly sweet, and tangy flavor.

Which rice is best?

Japanese short-grain rice is essential because its natural stickiness helps the onigiri hold its shape.

Can I prepare Tuna Mayo Onigiri in advance?

Yes. Wrap each rice ball individually and refrigerate for up to one day. Add the nori just before serving if you want it to stay crisp.

Can I use fresh tuna?

Certainly. Cooked, flaked fresh tuna can be mixed with mayonnaise as a substitute for canned tuna.

Why is Tuna Mayo Onigiri so popular in Japan?

Its creamy filling, mild flavor, affordability, and convenience have made it one of the best-selling onigiri varieties in Japanese convenience stores and supermarkets.

Final Thoughts

Tuna Mayo Onigiri is a timeless Japanese favorite that perfectly balances simplicity and flavor. The creamy tuna filling, soft seasoned rice, and crisp nori create a satisfying combination that's easy to make and even easier to enjoy.

Whether you're preparing a quick breakfast, packing a bento lunch, or looking for a portable snack, this homemade Tuna Mayo Onigiri recipe brings one of Japan's most beloved comfort foods straight to your kitchen. With its delicious filling and effortless preparation, it's a recipe you'll want to make again and again.