Until about 20 years ago, very few people outside Japan ate uni (sea urchin), so most of the world’s sea urchin was exported to Japan. Major producing countries included Chile, the United States, Russia, and China. Japan provided technical guidance to these countries, and today they produce sea urchin of quality comparable to Japan’s.
As sushi has gained global popularity, more people have begun eating sea urchin. A video of Los Angeles Dodgers player Freddie Freeman trying sea urchin for the first time in Tokyo—encouraged by his teammates—and reacting with surprise at how delicious it was went viral. It seems likely that even more people will develop a taste for sea urchin.
At the same time, rising sea temperatures and other environmental factors have reduced the seaweed that sea urchins feed on, leading to declining catches worldwide. As a result, prices at Toyosu Market have surged. For example, on January 5, 2026, at the first auction of the year at Toyosu Market, purple sea urchin fetched a record-breaking 35 million yen in a joint bid. The uni bowl made from it reportedly cost 1.1 million yen. While this is an extreme case, the typical price for a single piece of uni gunkan-maki ranges from 500 to 5,000 yen.
Now to the main question: what types of sea urchin are actually served at sushi restaurants?
There are six edible varieties of sea urchin in Japan. One of them, shirahige uni (collector urchin), is harvested only in small quantities in warm waters such as Okinawa, so it is not served at sushi restaurants in Tokyo. The varieties commonly served at sushi restaurants are:
- Murasaki uni (Purple sea urchin)
- Kitamurasaki uni (Northern purple sea urchin)
- Bafun uni
- Ezobafun uni
- Aka uni (Red sea urchin)
Closed seasons and peak harvest times vary by species. However, many sushi chefs do not clearly know which specific species they are serving. This is largely because Toyosu Market does not strictly label them by species. In practice, chefs infer the type based on season and harvest location.
Murasaki uni and Bafun uni are each further divided into two subtypes. In some regions, Murasaki uni is referred to as “kuro uni (black sea urchin)” based on its appearance. However, there is no species officially called black sea urchin—it is simply a type of Murasaki uni.
At Toyosu Market, sea urchin is typically categorized into three groups: Murasaki uni, Bafun uni, and Aka uni. This is the general commercial classification.
Broadly speaking, Murasaki uni, Bafun uni, and Aka uni prefer warmer waters and are harvested west of the Kansai region. In contrast, Kitamurasaki uni and Ezobafun uni prefer colder waters and are harvested in Hokkaido and the Tohoku region.
Fishing takes place year-round somewhere in Hokkaido, but each area has designated closed seasons. Kitamurasaki uni is not harvested on the eastern side of Hokkaido. Both Kitamurasaki uni and Ezobafun uni are harvested on the western side of Hokkaido, primarily from June through August.
The edible portion of sea urchin is the reproductive organ, which appears yellow to orange. Confusingly, in the sushi trade, Murasaki uni is sometimes referred to as “white,” while Bafun uni is called “red,” based on the color of the edible portion. Aka uni has only been commonly served at sushi restaurants for about the past decade; before that, the industry largely used the simple categories “white” and “red.” Incidentally, the “red” in Aka uni refers to the color of its shell.
A common rule of thumb is that Murasaki uni is yellow and Bafun uni is orange, but this is not absolute. Since sea urchin is often sold removed from its shell, it is actually difficult to distinguish the species visually—even though there are only five main varieties in circulation. The sea urchin sold at the first auction of 2026 was Kitamurasaki uni, not Murasaki uni. Even the media appeared to misunderstand this distinction.
In conclusion, when you visit a sushi restaurant in Tokyo, sea urchin is almost always served as a single variety in gunkan-maki style. There is a greater than 50% chance that it will be either Kitamurasaki uni or Ezobafun uni. High-end sushi restaurants may offer both varieties depending on the season. Traditional sushi establishments often prefer the lighter, more delicate flavor of Kitamurasaki uni. Restaurants with direct sourcing relationships may also serve Aka uni.
It is also common for Ezobafun uni to be labeled simply as “Bafun uni.” Even if different types were mixed, most customers would not be able to tell. If a sushi restaurant west of Kansai refers to it as Bafun uni, it is highly likely that it is indeed Bafun uni.