Seasoned Kombu: Japan's Sweet-Savory Onigiri Filling
味つけ昆布
By the Aoi's Japanese School Lunch team · November 8, 2026 · 2 min read
What seasoned kombu (ajitsuke kombu) is, how it's used in onigiri, what's usually on the label, and what to use if you can't find it.
In the video "Best Onigiri in Japan: Top 3 Rice Balls Ranked!," the third rice ball is filled with seasoned kombu. Seasoned kombu is kelp cooked in a sweet soy seasoning and sold ready to eat. The video says even Japanese cooks don't usually make their own for onigiri. They buy it.
What is seasoned kombu?
- Kelp cooked in seasoning. In Japanese it's 味つけ昆布 (ajitsuke kombu). Look for it with the rice toppings at Japanese grocery stores.
- Sweet and salty. The video says it tastes sweet and is especially popular with adults.
- Not dried kombu. Dried kombu is the stiff kelp used to make dashi stock. It isn't ready to eat as a filling.
- Not shio kombu. Shio kombu is thin strips of kelp coated in salt. Aoi uses it in her Ricchan Salad. It's a seasoning more than a filling.
How it's used in the video
- 7:08 The seasoned kombu comes straight from the package. The video description lists 8 g (¼ oz) for 2 onigiri.
- 7:09 Store-bought is the normal choice, even in Japan.
- 7:20 With no filling to cook, this onigiri is almost done as soon as you start.
What's on the label?
Products differ, but the Japanese listings we checked show kombu, soy sauce and salt. Those labels list soybean and wheat because of the soy sauce. If you avoid wheat or soy, check the label on your package.
It's also strongly seasoned, so a small amount goes a long way.
Can't find it?
- Use a little shio kombu. It's saltier and less sweet, so start with less.
- Make a quick version. This is a common home method, not one from the video. Slice softened kombu thinly, then simmer it with soy sauce, mirin and sugar until the liquid is nearly gone.
- Choose another filling. Tuna mayo and salmon are the other two rice balls in the same video.
Also in this video: Kewpie mayonnaise and the onigiri mold.
