Japanese convenience stores and supermarkets sell many different kinds of onigiri.
Some of the most common fillings are salmon, tuna mayonnaise, pickled plum, kombu, tarako, mentaiko, and okaka.
Ume means pickled plum. Salmon onigiri usually contains grilled or flaked salmon. Kombu is often seasoned and simmered seaweed. Tsuna mayo is tuna mixed with mayonnaise, while okaka is dried bonito flakes seasoned with soy sauce or similar flavors.
Tarako is salted pollock roe, while mentaiko is pollock roe seasoned with chili and other flavors. They can look similar, but mentaiko is usually the spicier of the two.
The exact product names can vary from one store to another.
For example, salmon may be labeled as sake, shake, yaki-zake, or beni-jake. Kombu may appear as kombu or kombu tsukudani, while mentaiko may be written as mentaiko or karashi mentaiko.
However, convenience-store onigiri still tend to use familiar, standard fillings. Even when the wording changes slightly, the main filling is usually easy to recognize.
If you can recognize key words such as sake or shake, ume, kombu, tsuna mayo, tarako, mentaiko, and okaka, you can usually make a good guess about what is inside without reading every part of the label.
For foreign visitors, the most reliable way to identify an onigiri is to look at the filling name printed on the package. Colors and pictures can sometimes help, but there is no nationwide color system. If you want to be sure, the written name is the safest guide.
Japanese people do not all choose onigiri in the same way. Some have favorite fillings they often buy, while others change depending on what they feel like eating that day or try new products.
Another thing many people pay attention to is price. Onigiri is often bought together with other food, so even if a filling looks good, someone may choose a cheaper option if one rice ball feels too expensive.
In practice, people often choose based on the filling, what they feel like eating that day, and the price.
If you learn a few of the standard filling names, you can usually tell what is inside even when the product name is written a little differently.
References
- 7-Eleven Japan, “Onigiri”
- FamilyMart, “Omusubi”
- Lawson, “Onigiri”
- Cross Marketing, “Survey on Onigiri”
