---
title: "What is onigiri? Japan's rice ball, also called omusubi"
description: "Onigiri is cooked rice pressed by hand into a triangle or ball, salted, filled and often wrapped in nori. Its shapes, its 2,000-year history, and the name omusubi."
url: https://kama-meshi.com/en/articles/onigiri
language: en
published: 2026-11-11
category: "Food and culture › Rice and rice dishes"
tags: ["RiceDishes", "Bento"]
author: "Oginoya Editorial Team"
publisher: "Oginoya Co., Ltd."
translations:
  zh-TW: https://kama-meshi.com/zh-tw/articles/onigiri
  ko: https://kama-meshi.com/ko/articles/onigiri
  zh-CN: https://kama-meshi.com/zh-cn/articles/onigiri
  zh-HK: https://kama-meshi.com/zh-hk/articles/onigiri
  th: https://kama-meshi.com/th/articles/onigiri
  de: https://kama-meshi.com/de/articles/onigiri
  fr: https://kama-meshi.com/fr/articles/onigiri
  es: https://kama-meshi.com/es/articles/onigiri
---

# What is onigiri? Japan's rice ball, also called omusubi

![Two triangular rice balls wrapped in dark sheets of nori, with white rice showing at the corners](https://kama-meshi.com/_astro/onigiri-wrapped-2020.rCgW6UoX_ZKMvtW.webp)

*Onigiri* is cooked rice pressed by hand into a triangle, a ball or a short cylinder, usually salted, with a filling such as pickled plum or salted salmon inside and often a sheet of nori seaweed around it. It is also called *omusubi*, and because it can be eaten with the fingers and carried easily, it has served as the meal of people working outdoors and of travelers.

## Rice pressed into shape

The plain word is *nigirimeshi*, "pressed rice", and onigiri and omusubi are its polite names. The rice is usually salted and shaped into a triangle, a ball or a *tawara*, a short cylinder with the form of a straw rice bale. Rice pressed in a mold instead of by hand goes by the same name.

The filling goes in the middle: *umeboshi* (salt-pickled plum), dried bonito flakes, salted salmon, cod roe, kombu, or *tsukudani*, foods simmered down in soy sauce. Umeboshi keeps the rice from spoiling and works as a side dish as well.

The shape varies by region. In Edo, the city that is now Tokyo, rice balls were round or triangular, and the triangle was the more common. In the Kansai region the standard is the tawara, and around Matsuyama in Shikoku it is a long triangle.

A rice ball toasted over a flame until the surface scorches a little, then coated with soy sauce, is a *yaki-musubi* or *yaki-onigiri*. It keeps well, which suits it to travel and mountain climbing.

![Two triangular rice balls grilled to a brown crust, on a white plate with blue stripes](https://kama-meshi.com/_astro/yaki-onigiri-2025.DIRARSA8_1h7IRl.webp "Yaki-onigiri, grilled rice balls, 2025.")

## From a lump of charred rice

In 1987 a lump of carbonized rice was dug out of the Sugitani Chanobatake site in Rokusei, a town that is now part of Nakanoto in Ishikawa Prefecture. It dates from the middle of the Yayoi period, about 2,000 years ago, and it is known as Japan's oldest onigiri. June 18 is Onigiri Day: the *roku* of Rokusei sounds like the word for six, and the 18th of every month is Rice-Eating Day.

In the Heian and Kamakura periods, from 794 to 1333, when an event was held at the palace or in a noble house, the servants were given *tonjiki*. This was steamed glutinous rice pressed into the long, rounded shape of a bird's egg and set out on stands in the garden. Tonjiki appears in *The Tale of Genji*, in the scene of the hero's coming-of-age ceremony, and it is regarded as the prototype of onigiri. Rice balls later came to be made with ordinary, non-glutinous rice.

A rice ball needs no dish. In the Warring States period, from the late 15th century to the end of the 16th, it was valued as food to carry, and it was the lunch taken to the fields. Rice balls were also the meal of emergencies such as fires and funerals, and they are still served after accidents and disasters.

The word nigirimeshi turns up in a story published in 1698, as a lunch taken out of a wrapping cloth. Late in the Edo period (1603–1868), the [*makunouchi* bento](https://kama-meshi.com/en/articles/what-is-bento) eaten at the theater held ten rice balls with konnyaku, grilled tofu, simmered dried gourd, simmered tubers, fish cake and omelet.

## How nori came to wrap it

Onigiri is usually wrapped in nori, though shaved kombu, pickled *takana* mustard leaves and dried wakame are used too. Dried nori is made by chopping fresh seaweed, spreading it in a frame the way paper is made, and drying it in the sun.

Nori farming began in the Kyōhō era (1716–1736) along the coast from Ōmori to Shinagawa, on what is now Tokyo Bay. With farming, tens of times more nori reached the market than before, and it became a product of Edo that ordinary people ate. Square sheets of nori appeared in the middle of the Edo period. A sheet of nori is lightly toasted before it goes around the rice, and the nori adds umami, from glutamic acid, and fragrance.

![Two triangular rice balls on a cream-colored plate, each with a band of nori around the lower half](https://kama-meshi.com/_astro/onigiri-nori-2021.bXN7g8O4_1Qj2wQ.webp "Onigiri with a band of nori, 2021.")

## The first ekiben was a rice ball

The first [ekiben](https://kama-meshi.com/en/articles/ekiben-history), the bento sold at Japan's railway stations, was two rice balls and pickled daikon radish wrapped in [bamboo sheath](https://kama-meshi.com/en/articles/ekiben-containers), sold at Utsunomiya Station in July 1885.

On October 15 of the same year, the day the railway from Takasaki reached Yokokawa, [Oginoya](https://kama-meshi.com/en/articles/oginoya-history) opened at Yokokawa Station and began selling an ekiben of its own: omusubi. From about 1955, ekiben with names like "such-and-such rice" or "such-and-such sushi" appeared all over Japan. The leading example was [Tōge no Kamameshi](https://kama-meshi.com/en/articles/what-is-kamameshi), which Oginoya put on sale at Yokokawa Station on February 1, 1958.

## Onigiri or omusubi?

Japanese dictionaries define onigiri and omusubi in the same way, as polite words for nigirimeshi. Oginoya itself writes omusubi for its ekiben of 1885.

Explanations of where the two words came from differ. One dictionary says that onigiri was originally a women's word. Another account holds that onigiri is the older of the two words and that omusubi began in the Edo period, as the refined speech of high-ranking women and of the shogun's inner palace. Under that account the food is the same and only the name is different.

## From something made to something bought

Seven-Eleven opened its first store in Japan in Kōtō Ward, Tokyo, in 1974, and began selling onigiri in 1978. In the 1970s, onigiri made at home were wrapped in nori straight after shaping, so the nori was moist. Seven-Eleven devised a hand-wrapped onigiri named Parikko Film, for which the buyer wraps the nori around the rice just before eating. At first only two or three sold in a day. The crisp nori got people talking, and in 1984 the company developed a "parachute" style of hand-wrapped onigiri.

As convenience stores took up onigiri, fillings that belong to the store-bought kind, such as tuna with mayonnaise, became standard. Seven-Eleven describes the change as onigiri turning from something people make into something they buy.

## References

- [Kotobank, "Nigirimeshi" (Encyclopedia Nipponica, Heibonsha World Encyclopedia and others)](https://kotobank.jp/word/%E6%8F%A1%E3%82%8A%E9%A3%AF-109185)
- [Kotobank, "Tonjiki"](https://kotobank.jp/word/%E5%B1%AF%E9%A3%9F-107111)
- [Kotobank, "Nori"](https://kotobank.jp/word/%E6%B5%B7%E8%8B%94-112508)
- [Kotobank, "Asakusa nori"](https://kotobank.jp/word/%E6%B5%85%E8%8D%89%E6%B5%B7%E8%8B%94-424045)
- [Kotobank, "Onigiri" (Digital Daijisen)](https://kotobank.jp/word/%E5%BE%A1%E6%8F%A1%E3%82%8A-453689)
- [Kotobank, "Omusubi" (Digital Daijisen)](https://kotobank.jp/word/%E5%BE%A1%E7%B5%90%E3%81%B3-454475)
- [Nakanoto Town, "June 18 is Onigiri Day"](https://www.town.nakanoto.ishikawa.jp/soshiki/kikaku/5/2/2/1389.html)
- [Ministry of Agriculture, Forestry and Fisheries, Hokuriku Regional Agricultural Administration Office, "Do you know about onigiri?" (PDF)](https://www.maff.go.jp/hokuriku/kokuei/nishihoku/pdf/06_47.pdf)
- [Ministry of Agriculture, Forestry and Fisheries, "Tracing the history of bento"](https://www.maff.go.jp/j/keikaku/syokubunka/culture/wagohan/articles/2209/spe9_02.html)
- [Ota City, "Learn about the nori of Ōmori"](https://www.city.ota.tokyo.jp/omori/ts_omorinishi/katsudou/miryoku/oomorinori.html)
- [Nori Japan, "The history of nori"](https://www.nori-japan.com/lecture/history/)
- [Seven-Eleven Japan, "50th Archive: the early years"](https://www.sej.co.jp/50th/archive/reimeiki/index.html)
- [Seven-Eleven Japan, news release, February 20, 2020](https://www.sej.co.jp/company/news_release/news/2020/202002201400.html)
- [Kotobank, "Ekiben"](https://kotobank.jp/word/%E9%A7%85%E5%BC%81-444219)
- [Oginoya, chronology](https://www.oginoya.co.jp/tougenokamameshi/history/)

Image credits (resized for display):

- [Ocdp / Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Onigiri_001.jpg), [CC0](http://creativecommons.org/publicdomain/zero/1.0/deed.en), 2020
- [Ocdp / Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Yaki-Onigiri_002.jpg), [CC0](http://creativecommons.org/publicdomain/zero/1.0/deed.en), 2025
- [Ocdp / Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Onigiri_002.jpg), [CC0](http://creativecommons.org/publicdomain/zero/1.0/deed.en), 2021