Humble onigiri is soul food in Japan

The word "onigiri" became part of the Oxford English Dictionary this year, proof that the humble sticky-rice ball and mainstay of Japanese food has entered the global lexicon.

The rice balls are stuffed with a variety of fillings and typically wrapped in seaweed. It's an everyday dish that epitomizes "washoku" — the traditional Japanese cuisine that was designated a UNESCO Intangible Cultural Heritage a decade ago.

Onigiri is "fast food, slow food and soul food," says Yusuke Nakamura, who heads the Onigiri Society, a trade group in Tokyo.

Fast because you can find it even at convenience stores. Slow because it uses ingredients from the sea and mountains, he said. And soul food because it's often made and consumed among family and friends. No tools are needed, just gently cupped hands.

"It's also mobile, food on the move," he said.

Onigiri in its earliest form is believed to go back at least as far as the early 11th Century; it's mentioned in Murasaki Shikibu's "The Tale of Genji." It appears in Akira Kurosawa's classic 1954 film "Seven Samurai" as the ultimate gift of gratitude from the farmers.

What exactly goes into onigiri? The sticky characteristic of Japanese rice is key. What's placed inside is called "gu," or filling. A perennial favorite is umeboshi, or salted plum. Or perhaps mentaiko, which is hot, spicy roe. But in principle, anything can be placed inside onigiri, even sausages or cheese.

Then the ball is wrapped with seaweed. Even one nice big onigiri would make a meal, although many people would eat more.

Yosuke Miura runs Onigiri Asakusa Yadoroku, a restaurant founded in 1954 by his grandmother. Yadoroku, which roughly translates to "good-for-nothing," is named for her husband, Miura's...