Introducing Onigiri Lab Sumiyoshi Nori Honpo Miyoshi Branch

Hello travelers! I’m Aikero, a Sarukuma writer who loves both bread and a good bowl of rice equally.

Today I’m taking you to Miyoshi in Koshi City, just north of Kumamoto City, to visit
【Onigiri Lab Sumiyoshi Nori Honpo Miyoshi Branch】.
Once you taste it, ordinary nori will never satisfy you again!
With a heartfelt mission to share the magic of premium nori (seaweed) with families and residents of northern Kumamoto, the renowned Sumiyoshi Nori Honpo — headquartered in Uto City — opened this Miyoshi branch.

The owner believes “great nori deserves to be the star of the meal,” and you can taste that philosophy in every simple, beautifully crafted onigiri (rice ball). The slightly sweet glaze brushed onto the seaweed is a secret recipe normally reserved for ajitsuke nori (seasoned seaweed) — a flavor only a true nori specialist could deliver!

Even better, kids get to enjoy a fun new experience: choosing between roasted (yaki) or dried (hoshi) nori for their rice ball — something you won’t find at typical onigiri shops.
The shop sits just off National Route 387, near the intersection by Country Park Kumamoto and the TKU Miyoshi Housing Exhibition Center.
It’s in the former Tandlmann location, so it’s easy to spot.
Here’s the parking lot.
There’s a small step at the entrance, but a ramp makes it stroller-friendly — perfect for visiting families.
Step inside, and it’s nori, nori, nori everywhere!
As you’d expect from a true seaweed specialist, the selection is breathtaking.
Their #1 bestseller!
・Luxury Furikake (rice topping) — 750 yen

Beyond the classic flavors, you’ll find plum, wasabi, and even unique options like curry!
Resealable aluminum packs keep everything fresh — great for travelers taking some home!
・Aluminum Pack Roasted Nori Series — 750 yen
Also used as an onigiri filling, the
・Luxury Tsukudani (savory simmered nori) — 750 yen
The same wakame seaweed soup served in the dine-in area is sold here too — buy a pack and you can recreate it easily at home or in your hotel room!
・Wakame Soup with Crumbled Roasted Nori — 550 yen
・Crumbled Dried Nori — 550 yen
Beyond the standard roasted nori and seasoned varieties…
…there are nori products labeled with the names of individual seaweed fishermen — the variety is incredible!
Premium nori prices reflect premium quality — making these jars wonderful Japanese souvenirs and gifts to bring home!

But how do you really unlock the magic of this everyday ingredient we so often pick by price alone? There’s only one answer!

Onigiri Lab Sumiyoshi Nori Honpo Miyoshi Branch — Recommended Menu

At the back of the shop, you’ll find a counter seating area.
This is where the real adventure begins — onigiri customized to highlight the deliciousness of nori in your own way!
・2-piece Set (with soup) — 880 yen
Choose any 2 fillings from a selection of 10 (no extra charge for any choice!).
The rice balls themselves are beautifully simple — just rice with a sheet of nori glazed in that secret seasoning sauce.
Its simplicity is exactly what lets the nori, sauce, and rice each shine.

・Extra Onigiri — 350 yen each
Want to add just one more for a child? No problem!

And here’s where it gets even more fun — you don’t just choose your filling. At Onigiri Lab, you also get to pick whether your onigiri is wrapped in roasted (yaki) nori or dried (hoshi) nori.
Not sure which you prefer? Don’t worry — you’re in for a treat.
Right at the counter, the owner pulls out a small grill and lightly toasts the nori before your eyes.

Owner couple

Half of each sheet is toasted — please taste both and pick your favorite!

Where else in the world can you choose your seaweed at an onigiri shop?
This is the kind of thoughtful, hands-on experience that earns the name “Onigiri Lab.”

Hold them up to the light and you can clearly see the difference!
The darker one on the left is dried nori; the lighter one on the right is roasted nori.

Dried nori has a rich, oceanic flavor — full of natural seaweed character. Roasted nori is crispier with a wonderfully toasty, fragrant taste.
Mark your nori choice and your fillings on the order sheet to design your dream onigiri.
Watching the onigiri being made right in front of you feels surprisingly like sitting at a high-end sushi counter — a uniquely Japanese experience.

The rice comes from Sakamoto-cho. The takana (pickled mustard greens) is made by the owner’s wife’s grandmother, and the tsukudani is the same product sold in the shop — every ingredient is carefully sourced.
Now the owner is brushing something onto the nori…

Owner couple

This is the secret sauce we use for our seasoned nori. Our company president loves seasoned nori, so we brush this special sauce onto the seaweed for every single onigiri.
It’s a flavor that only a true nori specialist can deliver.

As we chatted, fresh-made onigiri appeared right in front of us.
Onigiri, wakame soup, and Japanese tea — a quietly elegant combination that makes you feel deeply grateful for traditional Japanese cuisine.

The gentle sweetness of the secret sauce, the briny aroma of the sea, the rich natural flavor of the nori, and the perfectly tender, crisp texture — it’s astonishing how dramatically the right nori transforms a humble rice ball!
My fellow writer Kurubushi went for the lu rou fan (Taiwanese-style braised pork rice).
It was loaded with generous toppings.
Even the kids took huge bites and devoured everything in no time!
Onigiri are universally loved by children, aren’t they?
Getting to choose their fillings and even taste-test the nori turns lunch into a fun, interactive food adventure for kids.
The wakame soup is generously filled with wakame seaweed and crumbled dried nori — a mineral-rich combination that’s as nutritious as it is comforting.
Because of the counter-style seating, you can chat face-to-face with the friendly owner couple — themselves parents — making for a truly warm visit.
While waiting for our onigiri, the kids got to look at picture books about onigiri and play with cute nori-shaped wooden blocks. So thoughtful!
Onigiri are also available for takeout — perfect for picnics or enjoying back at your hotel!
・1 piece — 350 yen
・Lu Rou Fan style — 400 yen
・3-piece set — 1,000 yen

The 3-piece set saves you 50 yen!

Onigiri Lab Sumiyoshi Nori Honpo Miyoshi Branch — The Story Behind the Shop

I sat down with the owner couple to learn why they chose to open this shop in Koshi City.

Aikero

Sumiyoshi Nori Honpo’s main shop is in Uto City, so why open a branch here in Koshi?

Owner couple

Our biggest reason was wanting children, young families like ours, and people in northern Kumamoto — where there are very few nori specialty shops — to discover how delicious truly great nori can be.
I honestly used to think supermarket nori was “normal” and never thought twice about it.
But after meeting my wife — whose family runs Sumiyoshi Nori Honpo — and tasting truly premium nori for the first time, I was blown away. “Nori can taste THIS amazing?!” That moment changed everything.

Aikero

Truly premium nori is on a different level when it comes to texture and aroma.
I think anyone who tries an onigiri here will be amazed by the difference.

Owner couple

Nori is usually thought of as a side ingredient, but we believe “great nori can be the star.”
That’s why we want children to be able to easily experience truly delicious nori.

Aikero

I completely agree. Kids love onigiri, and a rice ball made with truly premium nori is a feast in itself!
It’s also unusual to be able to choose your nori. Are roasted and dried equally popular?

Owner couple

Just like fillings, everyone has their own preference for nori, so we offer the taste-test.
They’re about equally popular — some customers even pick one of each.
For what it’s worth, my wife loves dried nori, I prefer roasted nori, and our president loves seasoned nori. It really comes down to personal taste!

Aikero

That hands-on touch is exactly what makes a nori specialist’s onigiri so special!
Filling out the order sheet, watching the chef craft each rice ball — it really does feel like a high-end sushi experience that kids can enjoy too.

Owner couple

Our president really wanted to create a sushi-counter-style experience that lets us connect personally with each customer — that’s how this counter style was born.
We also play videos showing how nori is harvested and made on the TV behind us. We want customers to truly understand and appreciate nori as they enjoy it.

Aikero

Being able to taste the nori firsthand and then buy it on the spot is a wonderful experience.
What are some of your most popular products?

Owner couple

Almost everyone who eats here ends up doing some shopping afterward.
Our best seller is the Luxury Furikake.
It’s especially popular with kids.

Aikero

My kids love nori too. Even when they snack on it, I think “well, at least it’s nori!” (laughs)
Very few people dislike nori, so it makes a wonderful gift to bring back home too.

Owner couple

Although too much of anything isn’t great! (laughs)
Our own kids are always asking us to make them onigiri.
Customers also tell us nori is the perfect choice for gifts.

Aikero

Thank you so much for all the wonderful stories today!
Finally, do you have a message you’d like to share with our Sarukuma readers?

Owner couple

First and foremost, we want children and young families to discover how truly delicious nori can be.
Great nori deserves to be the star of the meal.
We hope visitors come to Onigiri Lab and experience the magic of premium nori up close.

Onigiri Lab by Sumiyoshi Nori Honpo is the place to taste rice balls that truly showcase the deliciousness of premium Japanese nori.
Nori is something we tend to pick by price — but once you taste this, there’s no going back!
If you’re traveling through Kumamoto, definitely make the trip out to Koshi City for an unforgettable onigiri experience~ (^^)/

Follow us on Instagram for daily updates!
Sarukuma shares lunch spots, parks, indoor play areas, and family-friendly travel info around Kumamoto.
Please follow us(*´∀｀*)

Frequently Asked Questions

※Information is current at the time of reporting. Prices and hours may change. Please check before visiting.