Category: Edomaesushi

Why do we use the counter “kan (貫)” for sushi?

When you sit at the counter and order nigiri a la carte, they will come out in pairs.* There is nothing wrong with counting these in the regular Japanese way “ikko (一個),” “niko (二個).”

*It is said that nigiri-sushi in the Edo period was bigger than it is today, and too big to eat in one bite. In the Meiji period, the custom emerged of splitting this one big portion into two to make more easily consumed portions, and this is why it is common to get sushi in sets of two. However, nowadays making one piece of nigiri-sushi at a time is not very efficient. We think it’s actually easier for the sushi restaurant to make them in sets of two. Of course, you can order them one by one.

But the sushi restaurant won’t count them like that. Formally, sushi is counted in this way: Ikkan (one piece), Nikan (two pieces).

We have absolutely no idea where the custom of using the “kan” counter came from. It’s also not clear when use of that counter for sushi started.

Of course, there are theories. For example, there is a theory that back at a time when a single unit of money was called “kan.” The price for one piece of sushi was around 1 ‘kan’, and the counting method gained popularity.

Let me explain in more detail. The term “kan” originally referred to a unit of weight, with 1 kan equaling approximately 3.75 kilograms. It was also used as a unit of currency, with 1,000 mon coins being called “1 kanmon.” During the Edo period, sushi was sold at stalls, and the price per piece was expressed as ‘mon’ or “kanmon.” It is believed that this price unit was later repurposed as a unit of quantity.

Incidentally, when sushi first appeared, most sushi restaurants were food stalls, and the price ranged from 4 mon (120 yen in current currency) to 8 mon (240 yen) per piece. The most expensive topping at the time, otoro, did not suit the tastes of the people and was discarded, while omelette (tamagoyaki) at 16 mon (480 yen) were the most expensive topping.

There is another theory that one sushi roll was counted with the counter for roll “巻” (also pronounced “kan”), then a different kanji was used for it later. However, these are just theories that were created after the fact and the mystery remains unsolved.

In addition, sushi restaurants are a world where the culture of craftsmanship remains strong, and there is a background of using specialized terminology to maintain formality and tradition. Rather than using terms such as “1 plate (hito sara)” or “1 piece (ikko),” using the term ‘1 kan’ gives a more “chic (粋)” impression and is said to embody the tradition and aesthetic sense of sushi culture. However, this is the reason why it is still used today.

Even if you ask the owner of a sushi restaurant, they’ll probably cock their head to one side, think for a moment, and tell you that the “kan” mystery may never be solved.

Sushi rolls wrapped in seaweed rolls are counted in units of 本 (hon/bon/pon) in the wrapped state, and when cut with a knife, the units change to 切れ (kire). While these units are fairly straight-forward for Japanese language speakers and easy to understand, only the enigmatic 貫 (kan) remains a mystery.

We hope this information will be helpful.

Revision date: June 18, 2025

Share this article

Do you know that there are rankings for Negitoro?

a photo of nakaochiFirst, what do you imagine when you hear the word “negitoro”?

Most people probably think of “Negitoro Gunkan” or “Negitoro Roll” served at sushi restaurants.

But the real “negitoro” does not have leeks!

The original name for negitoro was negitoru. It translates to chip away in Japanese. The name eventually evolved to negitoro.

Here we come to the point.

The original negitoro is made from medium fatty tuna or nakaochi* chopped up finely with a knife and then mixed with chopped green onions on top. But the tuna may be switched out with filler, leading to a variety in quality of the negitoro available.

First of all, the lowest in the ranking are the offcuts of tuna that can’t be made into sashimi (mainly Yellowfin or Albacore tuna) and this is mixed with vegetable oil and minced. The type of onion used is normally green onions. You can pick this type out because it will be whitish in color. This version is normally served at conveyor belt sushi.

The medium quality uses the nakaochi of cheap Albacore tuna or Swordfish.

High quality negitoro uses the nakaochi of Pacific bluefin tuna or Southern bluefin tuna. Sometimes the green onion shoots are then rolled up inside. If you have a chance to try negitoro in Japan, we recommend you try the top quality options without a doubt. One piece will probably cost around $15 USD. But that’s the price for the real thing!

Finally, let me introduce some negitoro trivia. There is a lot of flesh on the middle bone (spine) and the surrounding area for tuna and the like. This is called “nakaochi*”. Scraping the meat from this area surrounding the spine is known as “negitoru”, which is where the word “negitoro” comes from. In other words, the name “negitoro” is not actually from the words onion (negi) and tuna belly (toro).

What is negitoro like at Sushi restaurants?

Originally, the meat from the middle cut or in between the bones of the tuna was used for negitoro. In order to get meat from these parts, the chef would have to purchase an entire tuna, or buy the cut that includes the mid-ribs. However, both of these purchases are difficult for a single sushi restaurant, so now the chef chops the meat from the body with a butcher knife until it forms a paste that is sticky and smooth from the fat in the tuna. This paste is used for negitoro.

[sc_apply url=”https://sushiuniversity.jp/apply/”]

We hope this information will be helpful.

Revision date: July 30, 2022

Share this article

What is Kakushiaji?

In Japanese cuisine (Including Edomae sushi), subtlety is often the key to perfection. One such subtle yet powerful technique is kakushiaji, or “hidden flavoring”—an approach that may seem minor, but can make a significant difference in the final taste of a dish.

Kakushiaji refers to a technique where a single seasoning (For example, sugar, vinegar, soy sauce, salt, etc.) is added to a dish. The Kakushiaji contrasts with the finished dish’s flavor, and is added in an amount too small to notice when served. This produces a clear improvement in flavor.

Examples include adding a little salt to heighten sweetness, or adding a little vinegar to a simmered dish. Sometimes these combination of flavors can be quite surprising, like adding a touch of chocolate to a curry.

In its narrower sense, kakushiaji refers specifically to seasonings or spices that please the palate or the nose. However, in a broader interpretation, it encompasses all the nuanced techniques and invisible efforts that contribute to the deliciousness of a dish. This includes selecting quality ingredients, using seasonal produce, applying seasonings at the right time and in the right way, choosing appropriate tableware, and ensuring a beautiful presentation.

In essence, kakushiaji is not just about taste—it reflects the spirit of craftsmanship and attention to detail that defines Japanese cooking. It is the hidden touch that turns ordinary food into an extraordinary experience.

A list of Kakushiaji

  • soy sauce
  • miso
  • dashi
  • ketchup
  • Worcester sauce
  • mustard
  • sake
  • mayo
  • mirin
  • chocolate
  • coffee
  • cocoa powder
  • honey
  • spices (nutmeg, all spice, garam masala, cinnamon, cardamom, etc)
  • brown butter
  • chili oil
  • shio koji
  • amazake
  • yogurt
  • caramelized onions
  • sugar
  • cream cheese

Related contents:

What is a firm difference between sushi and western fish cuisine?

What is Koku?

We hope this information will be helpful.

Revision date: July 5, 2025

Share this article

What is Umami?

Umami describes the delicious taste of savory flavor essences. For many years, people held to the belief that humans can taste only four basic flavors (sweet, sour, salty, bitter) until a Japanese chemist named Kikunae Ikeda discovered a fifth flavor (glutamic acid) in the early 20th century.

The main umami ingredients are glutamic acid in seaweed, inosinic acid in dried bonito and meats, succinic acid in shellfish, guanylic acid in shiitake mushroom.

Many ingredients contain a wide variety of umami essences. In combination, they create a synergistic effect that produces an even more potent savory flavor.

[sc_apply url=”https://sushiuniversity.jp/apply/”]

We hope this information will be helpful.

Revision date: July 9, 2025

Share this article

Is the handmade ginger in quality sushi restaurants free?

The ginger served in sushi restaurants is called “gari”. Some people eat it endlessly, thinking that it’s free no matter how much they eat.

However, at high-end or traditional sushi restaurants where artisanal gari is made in-house, it may be included in the bill. This is because crafting delicious, high-quality gari requires considerable time, skill, and labor, and the cost of fresh, domestic ingredients can be so high that serving it for free would result in a financial loss.

In contrast, the majority of sushi restaurants use commercially produced gari, which is mass-produced by large food processing companies, many of which have factories in China or Southeast Asia. These manufacturers typically soak large amounts of ginger in an industrial pickling solution containing salt, vinegar, acidulants, sodium saccharin, potassium sorbate, and sodium metabisulfite.
Although the quality of this mass-produced gari has improved in recent years, some versions have crushed and may be artificially colored with plum vinegar to enhance their appearance.

On the other hand, homemade gari, especially when made in Japan, is prepared with a more delicate and refined approach. It is typically seasoned with rice vinegar and salt, with sugar used sparingly to provide a gentle sweetness. The result is crisp, chewy, and flavorful, retaining the natural pale yellow color of fresh ginger without artificial coloring. During the early summer season, when young ginger (also known as shin-shoga) is harvested, the price of domestic ginger can soar to several thousand yen per kilogram. Due to its high water content, 1 kilogram of raw ginger yields only about 300 grams after squeezing.

Making high-quality, handcrafted gari is both cost-intensive and laborious, as sushi chefs often prepare a year’s supply in advance. Once made, it must be stored in a refrigerator dedicated exclusively to preserving the freshness and quality of the gari. When you consider the cost, effort, and culinary craftsmanship involved, it becomes clear that homemade gari is far more expensive and distinctive than its imported counterpart. In fact, serving authentic, house-made gari is one of the key elements that sets high-end sushi establishments apart from the rest. And even if you’re not charged for it, eating too much can dull your taste buds, affecting your appreciation of the sushi’s delicate flavors.

How to Make Gari (Pickled Ginger)

  1. Slice fresh young ginger thinly.

  2. Place the slices in boiling water.

  3. Once the water returns to a boil, remove the ginger.

  4. Drain the slices in a colander.

  5. Spread the ginger out on a bamboo sieve (or similar) and press it firmly while still hot to remove excess moisture.

  6. Soak the ginger in a seasoned vinegar mixture for half a day to a full day.

Vinegar Mixture (for 4kg of ginger):

  • 3.8 liters of rice vinegar

  • 1.5 kg of sugar

  • 300 grams of salt

Related contents: CONDIMENTS FOR SUSHI

We hope this information will be helpful.

Revision date: June 10, 2025

Share this article

What is the difference between “鮨,” “鮓” and “寿司” (all ready “Sushi”).

As far as we know, there are three ways “sushi” is written on sushi restaurant curtains in Japanese kanji characters: 鮨, 鮓 and 寿司.

Do you know the difference? Most Japanese people don’t know the answer to this question.

This is because various spellings are used by sushi restaurants throughout Japan.

For example, in Hokkaido, “鮨” is used. Next, in Tohoku, Akita and Yamagata use “鮨,” Aomori, Iwate, and Fukushima use “すし,” and Miyagi uses “寿司.”

In Kanto, Gunma, Saitama, Tokyo, and Kanagawa use “鮨,” Ibaraki and Chiba use “すし,” and Tochigi uses “寿司.” The spellings vary by prefecture.

Incidentally, among the 42 prefectures (excluding Nara, Wakayama, Kochi, Saga, and Okinawa), the most common spelling is “鮨” with 20, followed by “すし” with 17, ‘寿司’ with 4, and “鮓” with 1.

Broadly, in the Kanto area 鮨 is generally used while 鮓 is more common in Kansai. 寿司 is used commonly everywhere in Japan.

 

On the other hand, of the three, only 鮨 and 鮓 are seen in ancient Chinese literature. 鮨 was seen as a dictionary entry as early as the 5th to 3rd centuries B.C., and it’s origin is described as combining “fish” and “shiokara” (briny flavor) resulting in the term 鮨.

On the other hand, in A.D. 1st to 2nd century dictionaries, “鮓” appeared, and is explained to depict “a storage container for fish.” Toward the end of the second century 鮓 was used for the term “narezushi”.

But around the third century, the briny meaning of 鮨 and the term “narezushi*” written as 鮓 started to be used interchangeably. That is how the words were imported to Japan.

In Japan, the character “鮓” was often used in literature from the end of the Heian era to the end of the Edo era. Eventually the use of “鮨” was revived during the Meiji era (for unknown reasons). It was a natural transition that Kanto came to use “鮨” and Kansai came to use “鮓”.

Incidentally, the kanji “寿司” was created from the phonetics. Its use for celebratory occasions became commonplace throughout Japan.

*”Narezushi (熟れ寿司)” is the primitive version of Japanese sushi. It means covering seafood with salt and then soaking in rice for a few years as a form of lactic acid fermentation, which brings out the acidity.

We hope this information will be helpful.

Revision date: May 31, 2025

Share this article

Assessing Fish at the fish market!

One important task of sushi chefs is going to Tsukiji (Toyosu) every morning, looking at fish with their own eyes and assessing the quality. Having a good eye is important in order to get the highest quality possible, but this is cultivated by experience. They are also constantly obtaining information from the fishmongers at the market regarding what the best fish of the season and their localities. It’s almost a game as to whether they can get high-quality fish at the optimum price everyday. The skills of a sushi chef start with this assessment.

[sc_apply url=”https://sushiuniversity.jp/apply/”]

We hope this information will be helpful.

Revision date: September 11, 2018

Share this article

Why do sushi chefs make the sushi in front of the customers?

A photo of sushi chef
It is enjoyable to see sushi chefs at work.

Everyone can relax and enjoy a meal at a familiar restaurant. However, when visiting a new restaurant for the first time, you may feel a little nervous and find it difficult to concentrate on the food. You may feel a sense of being out of your element.

The purpose of going to a sushi restaurant is to eat delicious sushi. There should be no disagreement about that. And many regular customers at sushi restaurants enjoy casual conversation with the sushi chefs. The topics range from sports like baseball and soccer to politics, economics, and the opposite sex. The more skilled the sushi chef, the more they can remember all the conversations in chronological order.

For travelers who don’t speak Japanese, it may be hard to understand, but sushi restaurants are the only places in the world where customers can have a direct conversation with the head chef.

When I mentioned this, someone argued that at teppanyaki restaurants, you can watch the chef’s performance while having a conversation. In our opinion, that’s the same as a street performer. The performance should take priority over conversation.

Sushi chefs look at all their customers and adjust the timing of serving food for each one. Of course, they also want customers to see their beautiful techniques, but there’s no special reason why they have to make sushi in front of customers.

So why do they make sushi in front of customers?

Generally, it plays an important role in enhancing the transparency in the cooking process and instilling trust in customers regarding hygiene management and quality maintenance. But that’s not all. Sushi chefs are expected to learn communication and create the right atmosphere on their own. Because sushi tastes better in a fun atmosphere than when eaten in silence.

We hope this information will be helpful.

Revision date: May 19, 2025

Share this article

There are two ways to make anago nigiri sushi, “skin-up ” and “skin-down”.

A photo of anago nigiri sushi
The appearance of anago nigiri sushi

“Anago nigiri sushi” is a type of sushi where eel, simmered and cut into a fillet, is placed on top of vinegared rice and brushed with a sauce called “tsume.” The head and bones of the eel are simmered to create a broth, which is then seasoned and reduced to make the tsume.

When cooked, anago (conger eel) becomes very tender. On the flip side, this means it also falls apart easily. “Falling apart” refers to the dish becoming mushy and falling apart. The fish’s bones and flesh become mushy, resulting in an unappetizing appearance.

There are two solutions to prevent falling apart.
The first is to wait until the anago broth has cooled before removing the eel. This is the most effective method to prevent falling apart. As the eel cools, the gelatinous substance in the flesh solidifies, allowing it to be easily handled even when the anago broth has cooled.

The downside of this method is that the eel solidifies in a curled shape. When using it for nigiri sushi, it might be more convenient if the eel is stretched out. Additionally, since the eel hardens when cooled, forcing it flat while it’s hard can cause the flesh to crack.

The second method is to cook the eel in a bamboo basket and remove it while it is still hot.

That’s all you need to do to prepare the anago.

Next, we will describe the characteristics of anago itself. The naval (actually the anus) in the middle of the body serves as the border separating the head part (top) and tail part (bottom) of the eel. The fat and umami are distributed better on the top. People used to say that since the bottom moves more it is more tasty. This applies to fish in general.

Additionally, in sushi restaurants, it’s also often said, “the top should be served skin-up and the bottom should be served skin-down.” Please refer to the following for explanations of skin-up and skin-down.

As shown in this image, skin-up means that the skin side is on top and the meaty side is on the rice.

As shown in this image, skin-down means that the meaty side is facing up and the skin side is on the rice.

To tell the truth,  anago easily melts apart when it is boiled and broth enters the part where it separates, so the appearance is not as appealing. In this case, it is better to make sushi using skin-up. But unless the crack is extremely obvious, whether to skin up or skin down is up to the sushi chef’s discretion. Skin-up can be cooked with tsume, and skin-down can be seasoned with salt and citrus juice to bring out the flavor.

For your reference.

We hope this information will be helpful.

Revision date: May 30, 2025

Share this article

The migrating route of Inshore Pacific bluefin tuna and fishing place!

An illustration of Kuro maguro main prodution area
This is the migration route of Kuro maguro (bluefin tuna).

Tuna caught in the coastal regions of the Japan Sea is notable as the best bluefin tuna in January. Iki, a small island in Kyushu area is one of the famous ports for tuna.

In February and March, the tuna auction market becomes slack due to rough weather. Just a few tunas from Nachikatsuura where is also the famous port for tuna are on the market.

In March and April, tunas become thin because their eggs need many nutrients.

In May, large tuna is seldom seen in the Tsukiji Fish Market. Even if there is, its body is really thin. “Kinkaimono” which means a shore-fish is generally considered as high-class tuna, but in this season, imported tuna is useful instead.

It is said that Pacific Bluefin tunas spawn around Japanese waters between Taiwan and Okinawa in April and May. And then, they go up to fertile, north sea along the eastern coast of Japan.

In June, “Chubo” which is young and small tuna is taken hugely off the coast of the Sea of Japan. The school of Chubo begin moving northward in this season.

In July and August, tunas can be seen occasionally but their bodies are still thin. Instead, Boston Tuna which is caught in the Atlantic Ocean and nicknamed “Jumbo” is on the market. Its fresh is softer than “Kinkaimono” and it doesn’t have medium-fatty part which “Kinkaimono” has.

In September, Boston Tunas are at their best with plenty of fat on them. The best season of Boston Tuna is limited and ends in October. But fortunately, Japanese tunas come into season.

The school of tunas split up into two groups, the one takes Pacific Ocean route and another takes the Japan Sea route and both of them move northward along the Japanese Islands. Some of them reach the Tsugaru Strait where and the season of Tuna begins from September to next January. Oma town and Toi town is famous nationwide for its catch of tuna from the Tsugaru Strait. The flavor of tuna in September is still weak but it becomes stronger in October. In November, feed of tunas such as Pacific saury or Japanese common squid with plenty of fat increase and flavor of tuna also gets stronger. In December, the peak season comes around.

A catch of tuna falls off in January and it enters the final season. The temperature of sea water gets cold and feed of tuna, squids decrease and the fishing season in this area ends.

Related contents: TYPES OF TUNA

[sc_apply url=”https://sushiuniversity.jp/apply/”]

We hope this information will be helpful.

Revision date: August 20, 2018

Share this article

Tuna is matured to rest before it is used.

Once a bluefin tuna is caught, it arrives at Toyosu fish market within a day or two. However, that fish is not used as a sushi topping that day. No matter how good the tuna is, it starts very stiff and is not in a state where it should be eaten. The meat is hard and the white muscle lines are left in your mouth. The odor and acidic taste of the red meat is strong and the unique sweetness of the fish is nowhere to be found. After it has rested the muscles soften, bringing out the fat.

Then, when the sushi chef gets the tuna, he first separates the red, lean meat and the fatty toro portion, rewraps them separately, seals them in plastic, and puts them on ice. Next is waiting for the “young” meat, not yet suitable for eating, to mature. The number of days the fish will be rested depends on the size of the fish and the temperature. The smaller the cut and the warmer the temperature, the shorter the rest time. Generally the time is from 3-14 days.

The tuna wholesaler may also decide on the aging period independently. There is no right answer for this aging period, and it is decided based on the experience of the sushi chef.

This “young” fish not ready for consumption is a fresh, deep color but as it matures the color darkens, the fat is brought out and becomes a fleshy color. Proper care must be taken because if it’s rested for too long, the color changes too quickly.

As an aside, right after the tuna cutting show, it has not yet aged enough to be delicious. The color is light, and the production of umami ingredients such as inosinic acid is not sufficient. This is a show for advertising purposes.

Related contents: TYPES OF TUNA

We hope this information will be helpful.

Revision date: March 11, 2025

Share this article

Why do most sushi restaurants have 8 seats at the counter?

A photo of sushi restaurant
Most sushi restaurants have around 8 seats at the counter.

The main reason why many sushi restaurants operate with only around eight counter seats is to ensure the highest quality and to highlight the artistry of the chef.

In traditional sushi establishments, only the master chef prepares the nigiri sushi. Occasionally, there may be a senior apprentice who is allowed to make sushi as well, often someone on the verge of opening their own restaurant. In many cases, however, junior apprentices are not even permitted to handle knives. This is because the way a fish is cut can significantly alter its texture, which in turn affects the overall flavor and quality of the sushi. There is a noticeable difference between sushi prepared by the master and that made by an apprentice.

Equally important is the ability to read the subtle, often unspoken cues of the customer. Adjusting the pacing of the meal, the portion sizes, and the sequence and selection of ingredients is considered the true essence of counter-style sushi. For this reason, apprentices are first trained not in technique, but in observation. Learning to quietly watch the master’s rhythm, the timing of each course, and the space maintained between chef and guest forms the foundation of their training. Even without being explicitly taught, they absorb how to “read the customer” by emulating the conduct of seasoned chefs.

The true skill of a sushi chef lies not merely in serving sushi, but in the precise moment of “shaping” the shari and the topping. Sushi carefully prepared one piece at a time in front of your eyes is like a live performance. Everything from the amount of rice, the thickness of the fish, the pressure of the fingertips, and the movement of the hands is done in full view of the customer, allowing the skill of the chef to be conveyed directly. It feels like watching a work of art come to life before your eyes.

A sushi counter with just a few seats is not merely about space efficiency—it is a deliberate design meant to create an immersive “five-sense experience” that engages taste, sight, sound, smell, and even the feeling of time itself. The intimate and quietly focused atmosphere allows guests to step out of their everyday routines and appreciate sushi as a form of art. Each piece becomes more than food—it becomes a moment.

We hope this information will be helpful.

Revision date: June 19, 2025

Share this article

Why can’t Sanma (pacific saury) be caught?

On the Pacific Ocean side of Japan there is a three-way deadlock between sardines, mackerel and Pacific saury. There is a theory that the species take turns with increasing and decreasing populations. In recent years there has been an increase in sardines and, in turn, there has been a decline in Pacific saury.

[sc_apply url=”https://sushiuniversity.jp/apply/”]

We hope this information will be helpful.

Revision date: July 30, 2018

Share this article

What is the difference between maturing and rotting?

When fish die, stopping the supply of ATP (Adenosine Triphosphate), the source of muscle energy, the muscle fibers gradually harden. As time passes, it gently dissolves and the ATP breaks down, changing into umami components due to self-digestion.

ATP is broken down as follows, but in living fish, only the reaction up to AMP occurs. Once broken down to AMP, it is regenerated as ATP.

ATP→Adenosine diphosphate (ADP)→Adenosine monophosphate (AMP)→inosinic acid (IMP)→hypoxanthine riboside (HxR)→Hypoxanthine (Hx)

In fish after death, inosine monophosphate (IMP) is produced from AMP by an enzyme called adenosine deaminase (ADA). This is called maturing. Inosine monophosphate is not found in cells immediately after death. Maturation is required for the production of inosine monophosphate. If it goes further, it will go bad and HxR (inosine) and Hx (hypoxanthine) will be produced.

The umami created by self-digestion of ATP is “maturing (Jukusei)” and the process after that is “rotting.”

We hope this information will be helpful.

Revision date: March 17, 2025

Share this article

Sushi trends

Foods made to go well with alcohol like ‘shiokara’ salted fish parts or dried mullet roe, don’t go well with shari (vinegar rice). Also, restaurants mainly serving alcohol and foods to pair with it are either bars or Japanese cuisine restaurants that may also serve sushi, but not Edo-style sushi. Many years ago sushi chefs would even get angry saying things like, “Sushi restaurants are not bars. If you want to drink, go next door!” Even Rosanjin wrote, “Sushi restaurants that served alcohol first appeared after WWII. Before the war sushi was served with tea.” In other words, Edo-style sushi restaurants originally didn’t serve alcohol. Perhaps it is true that the increase in sushi restaurants that feel like bars is a natural progression with time.

[sc_apply url=”https://sushiuniversity.jp/apply/”]

We hope this information will be helpful.

Revision date: July 9, 2018

Share this article

Copy Protected by Chetan's WP-Copyprotect.