Sea urchin has a creamy texture and rich flavor, with hints of natural sweetness and seaweed aroma. It leaves a lingering, rich umami flavor on the tongue. The acidity of the vinegared rice perfectly complements the sweetness of the uni. This is the general opinion of people who love sea urchin.
But some people say that “Sea urchin in a wooden box (called ‘hako-uni (箱ウニ)’ or ‘ori-uni (折ウニ)’ or ‘boxed sea urchin’) has a bitter medicine taste”.
The bitterness of sea urchin can be attributed to several factors, including changes in components due to decreased freshness, natural variations in taste depending on species or individual differences, the influence of the quality of seaweed used as feed on flavor, and the use of “potassium aluminum sulfate” (commonly known as alum) to enhance preservation and prevent deformation.
This alum treatment can also impart a distinctive bitterness, astringency, and metallic taste, making it a well-known cause of bitterness. As a result, many high-end sushi restaurants use sea urchin that is labeled as “additive-free” (no alum used).
If you’ve ever tried a sea urchin that tasted bitter*, this may be the reason.
*An “off flavor” that takes away from the primary good tastes.
What is saltwater sea urchin?
Sea urchin soaked in brine without using alum (called ‘ensui-uni (塩水ウニ)’ or ‘saltwater sea urchin’) is also commonly found. There is also a new technology that doesn’t use alum. In this method nitrogen water (water from which oxygen has been removed and then nitrogen dissolved) is used when sealing. The effect of replacing oxygen with nitrogen is inhibited oxidation, maintaining the freshness of the sea urchin.
Since it is sold soaked in saltwater with a salt concentration nearly identical to seawater, it has no bitterness or astringency, allowing you to enjoy the natural sweetness, umami, and seaweed aroma of the sea urchin, as well as its fluffy texture and juiciness. While it has a short shelf life, it is favored by sushi restaurants and high-end Japanese restaurants that prioritize quality. However, it is prone to losing its shape, so handling requires caution, and it is recommended to consume it as soon as possible after purchase.
About 200 years ago (around 1810-1830), Yohei Hanaya opened up the oldest nigiri sushi restaurant in Japan. It is said that this was the beginning of edomaesushi. As expected, none of the restaurants remain to this day, no matter how popular they were in those days. However, if relating to those lasting more than a century, as many as 10 still exist in Tokyo. It is such a surprise and many respect that they’ve managed to survive, still keeping their business running now. We will introduce those old restaurants in the order of its establishment.
KUDANSHITA SUSHIMASA
First started as a stall in 1861 at Nihonbashi area, relocated to Kudanbashi and then opened the restaurant in 1923. The beauty of wooden architect managed to survive the war and it has a 100-year history. They carefully prepare sushi ingredients with appropriate amount of vinegar and salt. Take Kohada for instance, they adjust the amount of salt depending on the thickness of fish fillet, fat content, temperature and humidity of the air. Check the glossiness of the vinegared kohada fish, and decide the best timing to serve. Enjoy superb sushi prepared with the traditional recipe passed on for generations.
JANOMEZUSHI HONTEN Established in 1865
BENTENMIYAKOZUSHI Established in 1866
YAHATAZUSHI Established in 1868
During the end of Edo period, many of samurai lords who had served for Tokugawa government lost their jobs. Many of them disguised themselves as dango rice dumpling seller. The first owner of Yahata-zushi was one of them, started the business as dango rice dumpling stall and then the second generation owner began serving sushi. The fourth and fifth chef now run the kitchen behind the counter. The fourth chef has a 62-year experience and he is the respected patriarch chef in Tokyo and serves traditionalEdomae-style sushi with careful preparation. The fifth chef adheres to basic principle of sushi making while embarking on new-style. He uses sun-dried salt produced in the French Basque Country for well-matured akami red fish such as tuna, and sea urchin from Hokkaido. Other must-eat ingredients are, the highest quality tuna from long-time partner vendor at Tsukiji market and rare tuna caught at the sea near Miyakejima island and matured for good five days.
OTUNASUSHI Established in 1875
YOSHINOSUSHI HONTEN
Opened in 1879, Yoshino sushi has served excellent Edomae-style sushi. Now the fifth-generation owner runs the restaurant. The second-generation owner first started using Toro, fatty tuna meat while most of the chef discarded it. That was because food freezing was not in widespread use at that time and fatty content of fish went bad quickly. Soon Toro was quickly raved by their regular customers as delicious treat. First it was called “abu” as it came from “abura” meaning fat in Japanese, but it didn’t sound as good as it tastes, so they changed it to “toro” meaning mild and tasty. They will feed you interesting stories to go along with sushi dish. One of them is that they had never considered Gunkan roll of ikura and uni sea urchin as sushi since Gunkan never requires hand rolling techniques as other hand roll sushi does. They use only salt and vinegar to make sushi rice not a slight use of sugar and mirin. And then they carefully prepare fish ingredients to go with vinegared rice. Enjoy delicious sushi dish however you like in a casual atmosphere.
The Art of Scent in Sushi Dining: A Matter of Courtesy and Respect
Refraining from wearing perfume is not merely about etiquette—it is a quiet expression of attentiveness and grace.
Sushi is a culinary art that engages all five senses—it is to be appreciated with the eyes, tasted with the tongue, and experienced through the nose. Among these, scent plays a particularly crucial role in shaping the overall impression of each piece.
Smell—whether orthonasal (through the nose) or retronasal (through the back of the throat while chewing)—is essential to how we experience flavor. When we eat, aroma compounds rise from the mouth to the nasal cavity, enhancing the taste of food. This is why, when we catch a cold and our nose is blocked, food seems tasteless. In fact, if you pinch your nose and drink orange juice, you might not even recognize its flavor. This clearly demonstrates just how deeply scent influences what we perceive as taste.
For instance, the umami of squid is not produced through the typical ATP-to-inosinate transformation seen in many fish. Instead, its flavor comes from the synergistic effect between adenosine monophosphate (AMP) and glutamic acid. This combination is said to produce a milder umami compared to ATP and glutamic acid, which is why freshness and texture become all the more important. Rather than allowing the squid to age, it is best enjoyed while still fresh, with its slightly firm, crisp bite intact.
Moreover, the gentle sweetness of squid is believed to come from taurine, and appreciating that subtle flavor requires an environment free from interfering scents. A strong perfume can easily mask such delicate nuances, making it difficult to fully experience the mild umami and sweetness that squid offers. To savor this gentleness, it is essential to refrain from wearing strong fragrances.
In the world of sushi, there exists the philosophy of “listening to the voice of the ingredients.” To bring out the natural flavor and aroma of each element, sushi chefs deliberately avoid excessive seasoning or added scents. They pay meticulous attention to factors like temperature, humidity, and even the angle of the knife.
Take, for example, the lean red meat of bluefin tuna. It is the sushi chef’s skill that determines the balance among its faint acidity, sweetness, and bitterness—none of which should overpower the others. If just one note dominates, the depth and complexity of the tuna is lost. Chefs carefully assess this balance to craft each piece of sushi.
There are sushi chefs who dislike gunkan-maki made with Kitamurasaki uni.
Similarly, with Kitamurasaki sea urchin, its fragrance is so delicate that some chefs choose not to wrap it in nori (seaweed), which might overpower its scent. This is another example of the deep consideration given to the ingredient’s natural aroma—a hallmark of the sushi chef’s philosophy.
In such a precise and sensitive culinary context, the intrusion of strong perfume from outside can become a serious disruption. If scent alters the perception of taste, both the chef’s craftsmanship and the ingredient’s unique character are diminished. Choosing not to wear perfume is, therefore, a simple yet meaningful way of showing respect for the chef’s work.
Additionally, most sushi restaurants—especially those with counter seating—are shared spaces, where diners sit mere inches apart. In such close proximity, even a modest amount of fragrance can affect the experience of neighboring guests. Strong scents can hinder their ability to enjoy the meal, making consideration for others not just polite, but necessary.
This kind of restraint reflects a fundamental virtue in Japanese culture: humility. In Japan, harmony is valued over self-assertion, and understatement is seen as a form of beauty. Refraining from wearing perfume is not merely about etiquette—it is a quiet expression of attentiveness and grace. Such mindfulness allows one to truly understand and appreciate sushi culture with both reverence and respect.
We really don’t understand but there is a regulation, that taking photos is prohibited at a seafood wholesale market. And its visiting hours have recently changed from 10am（11am） started from 15 June, 2018.
Even though cameras are forbidden as a rule, if you ask intermediate wholesalers for permission, they will gladly let you take pictures. It doesn’t seem quite right to me to have such a rule, as if it were an art museum.
We would like to thank all the intermediate wholesalers who willingly accepted me for shootings at their shops. We are praying you will carry on more thriving business.
More and more visitors from overseas are making a point of timing trips to Tokyo during the cherry blossom season. Guidebook in their hands, they head to Meguro River, Ueno Park, Sumida River, Chidorigafuchi Park, or another popular spot. It goes without saying that the blossoms are beautiful in all of these locations.
However, to be frank, there are so many people sometimes it’s hard to tell if you’re there to see blossoms or to see crowds. If you’re visiting Japan and you’d like to really experience cherry blossoms, we recommend Shakujii River.
Around 1000 trees bloom on both sides of the river and there are very few people, making it perfect for enjoying cherry blossoms on a stroll. There are actually more cherry blossoms here than on Meguro River or at Ueno Park.
After enjoying the scenery, stop by Makitazushi, established in 1972. Entering this flagship shop of Nakaitabashi is like stepping back in time to the Showa era (1926-1989). Make sure to splurge and order the special sushi selection for JPY 3100.
Location : A few minutes walk from Nakaitabashi Station on the Tobu Tojo Line
This refers to Norimaki, originating from Kanpyo maki. Now the core of Norimaki may be made from a number of different ingredients, but the most important part of Norimaki is not the ingredients inside, but the Nori (seaweed). There is a tendency for foreigners to dislike black-colored food, but Nori has a fresh sea scent, and a high amino acid and umami content, so it’s worth a second look.
The Nori used in Norimaki and Gunkan-maki is essential to Edomae sushi. The Nori used in sushi absolutely must have good fragrance and crispiness, melt in your mouth and have the right coloring. The combination of selecting the quality and source site of Nori and using different Nori according to the sushi topping is one of the things sushi chefs are particular about. During the Edo era, the sea near the area that is now Omori in Tokyo was the largest production site of Nori. However, with the reclaiming of Tokyo Bay, Nori can no longer be caught in Omori. Now, places like the Ariake Sea, Seto Inland Sea and Tokyo Bay are famous for producing high-quality Nori.
*Japanese terms will be italicized on sushi ingredients page.
There are only high rank toppings such as rich tasting sea urchin (Uni), salmon roe (Ikura) and herring roe (Kazunoko). All different from other sushi toppings when it comes to a texture and flavor. A lot of them have become widespread ever since the technique of gunkan style sushi was established after the war. There are also sushi toppings made from other than fish and shellfish.
*Japanese terms will be italicized on sushi ingredients page.
Crustaceans like shrimp and crab are sushi toppings overflowing with their distinctive sweetness.
Except for Kuruma ebi, Ebi and Kani (shrimp and crab) were introduced as sushi toppings after WWII. The sweetness of shrimp is stronger when eaten raw. There is still a sweetness remaining in boiled shrimp, but it’s weaker. Instead, the umami gets stronger and the texture is also completely different than when served raw. When boiled the fiber is more apparent and it can be bitten clear through. Kuruma ebi is one of the traditional sushi toppings of the Edo period.
The umami of shrimp is sweeter than that of crab. The sweetness comes from the amino acids contained in the extract: glycine, arginine, alanine, propurine, and betaine. In particular, Kurumaebi and amaebi are particularly rich in glycine. On the other hand, umami is related to ATP decomposition-related substances.
This painting depicts “Matsu no Sushi,” which was famous as the most extravagant sushi in Edo. A child is begging for shrimp sushi.
Crab wasn’t originally an Edomae sushi topping. However, there is a special sweetness that oozes from the gaps in the fibrous body. The umami of crab is the amino acids in the extract component. Among crabs, hairy crabs have the most amino acids, while those of snow crabs, a high-end winter delicacy, are less abundant than those of hairy crabs, and therefore less rich in flavor. Nucleic acid-related substances are mainly CMP, but ATP-degrading substances such as AMP and inosinic acid are also involved in the umami taste. The main component of sweetness is glycine betaine, a sugar alcohol-based component.
*Japanese terms will be italicized on sushi ingredients page.
<Ebi/Kani－Prawn/Crab>
Aburagani－Blue king crab (Paralithodes platypus (Brandi,1850))
Aka ebi－Argentine Red Shrimp (Pleoticus muelleri (Spence Bate, 1888))
Shellfish has been a traditional sushi topping started off with the origin of Edomae sushi. Its distinctive texture is fascinating, but the thing is, all kinds are expensive. As a sushi topping, it is placed between rich and light in flavor, and functions as a palate refresher.
The texture, flavor and fragrance differ greatly depending on the type and most people either love or hate Shellfish toppings.
A characteristic of the taste of shellfish is that it is both refreshing and rich. This is presumably due to succinic acid. It is known that if succinic acid is removed from the shellfish extract component, the umami of shellfish also disappears. However, the umami of shellfish is not due to succinic acid alone, but to the synergistic effects of amino acids such as glutamic acid, glycine, alanine, arginine, and betaine, which are present in the extract, and adenylic acid, a nucleic acid-related substance.
Kai is another topping type that has been eaten as Nigiri sushi since it was invented. Hamaguri is essentially a type of shellfish, but when in the Nigiri sushi world, it is generally lightly seared and then marinated in broth, so it is classified as Nimono.
*Japanese terms will be italicized on sushi ingredients page.
The Japanese love this strong umami coming out of its creepy features. These are sushi toppings that show their presence in your mouth.
There are over 450 types of Ika (squid) in the world and over 100 types just in the seawaters around Japan. Ika is essential to Japanese cuisine and is found in many recipes for home cooking. It is a representative of ingredients for common people that is both affordable and delicious. There are also many different types of Ika used as sushi toppings, and certain Ika are used during certain seasons, each with a unique flavor.
Tako (octopus) is a popular sushi topping at every sushi restaurant. However, preparing Tako from its raw state is very labor intensive. Some restaurants boil it, while others use “Sakura-ni.” Elaborate efforts are made at the restaurant in order to prepare a topping that can be bitten through and emit a delicious fragrance. Needless to say, when prepared raw, it is thoroughly kneaded by hand. It may be struck with the crest or wooden pestle of a kitchen knife, or boiled with roasted green tea, incorporating techniques from Kansai dishes. When Tako is prepared as Sakura-ni*, it is classified as Nimono.
*”Sakura-ni” refers to stewing octopus in sake, mirin and soy sauce to soften it, turning it into a shape that resembles cherry blossom (sakura) petals.
Japanese terms will be italicized on sushi ingredients page.
Hikarimono is a name unique to the sushi industry, and as the name implies, it refers to fish with shiny surface skin.
Hikarimono (Silver-skinned fish) includes horse mackerel, mackerel, sardines, sillago, and gizzard shad, generally referred to as blue-backed fish. Hikarimono all have high-fat content. It is approximately 7% in gizzard shad and horse mackerel. It is about 16% in mackerel. The taste is heavy. Many of the fish in this category lose their freshness quickly, so the preparations differ greatly from restaurant to restaurant. They say that you can tell how well a restaurant is doing by which Hikarimono they serve. This may be why many restaurants make sure to work hard on their Hikarimono.
Tachiuo really does look like a sword from the outside, so it seems like it should be classified as Hikarimono, but it’s actually Shiromi. In the sushi restaurant sector, Hikarimono refers to sushi toppings for which Sujime is used in the preparations. Furthermore, there are chefs who classify Shima aji as Hikarimono when the silver skin is left on, and Shiromi when the skin is removed. There are many people finding it hard to eat but it is actually healthy and rich in nutritive value.
*Japanese terms will be italicized on sushi ingredients page.
Akami generally refers to red-colored meat like beef and fish meat. The typical Akami fish are tuna and bonito. Its fatty and rich taste gives you satisfaction like “This is the sushi”. The meat gets its red color from the high hemoglobin and myoglobin content specific to migratory fish. At a sushi restaurant, when you order Akami, you will be served tuna. The word Akami exists for tuna.
*Japanese terms will be italicized on sushi ingredients page.
What does sea urchin sushi taste like?! 
Today, we are happy to announce that Sushi University has just started up a sushiblog !