The migrating route of Inshore bluefin tuna and fishing place!

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.


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Revision date: August 20, 2018

Tuna is allowed to rest before it is used.

Once a bluefin tuna is caught, it arrives in Tsukiji fish market within a day or two. However, that fish is not used as a sushi topping that day. No mater how good the tuna is, it starts out 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 and, 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.

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.


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Revision date: August 13, 2018

What is Uwami and Shitami?

Large fish that are caught are always kept and transported on their side with their heads facing left from the port to the market and to the restaurant where they are served. The part of the fish facing down when in this position is called “Shitami” or the “bottom body” and the part facing up is called “Uwami” or the top body. The Uwami costs more than Shitami. This is because the Shitami takes on the weight of the Uwami, reducing the freshness and possibly causing cracks in the body (cracking occurs on the edges of the muscles).


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Revision date: May 21, 2018

What is the difference between the taste of marbled and lined fatty tuna?

Marbled tuna is the part in which it looks like the fat has fallen like a frost and melts like snow on your tongue then leaving only the umami taste.

The lined fatty tuna (jabara) is the part that has white fat lines running through it and distributes a surge of aroma and umami flavor throughout the mouth. After that the potent fatty umami fills your mouth. The way the fat melts in your mouth differs, so everyone has their own preference.


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Revision date: April 9, 2018

Can’t-miss Tokyo sushi toppings (Meji Maguro)

Meji Maguro (AKA: Meji) caught in fixed net fishing is one type of sushi topping that you really should try. Meji is the larval fish of Pacific bluefin tuna, made and served at expensive restaurants, but not usually available as Edo-style sushi. Its fat is lighter and it doesn’t have the impact that fatty tuna has. Efforts are put into seasoning to avoid this. Using a pinch of ginger, Japanese basil or onion between the topping and rice, along with the wasabi, really brings out the fresh flavor of the young fish as well as the sweetness of this fatty part.


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Revision date: March 26, 2018

Why is sushi with tuna topping so expensive?

A purchase of raw tuna costs at least JPY 30,000 per kilogram. Furthermore, good tuna is judged not only by taste, but appearance is also highly regarded.

The surface is gradually oxidized by letting it sleep (mature) and the sushi chef makes sure that parts are cut of as they change color, when the timing is perfect for both the taste and appearance. In other words, skin is taken from the freshly purchased tuna, the meat of the fish darkened by blood (the blackened area that can’t be used as sushi toppings) is removed, the parts that have changed color are shaved off and then only the remaining, best parts used as toppings are left.

This is why the price is high.


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Revision date: February 5, 2018

Tuna was not a premium fish during the Edo period

During the Edo period, tuna was not highly valued as a sushi topping and it was referred to as “Gezakana” meaning that it was inferior to normal fish. The reason was the big size of the tuna. At this time there was no ice, so tuna had to be salted. It was cut into blocks, salt was spread all over and in it, and that was it. At Uogashi (the market prior to Tsukiji) it was treated at shops that specialized in salting fish. The dark, discolored, salty chunks of flesh really were nothing but “Gezakana*”.

*Gezakana -Relatively low-cost sushi ingredients, such as gizzard shad and horse mackerel. Bluefin tuna used to be also called gezakana in the Edo period, for losing its freshness easily.


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Revision date: December 30, 2017

You know fatty tuna, medium-fatty tuna and lean tuna, but have you heard of the more rare parts of the fish?

A single bite of the same bluefin tuna differs greatly depending on the part of the fish it came from.

The body of the fish is broadly categorized into the dorsal (back) and the ventral (belly) sides, which taste completely different. Of course the meat near the head tastes completely different from the meat near the tail. If you dig even deeper, there are parts that aren’t as well-known as the Ohtoro (fatty), Chutoro (medium-fatty) and Akami (lean) tuna meats. I’d like to explain those now.

Hachinomi” is the meat from the crown of the head. It is fatty and rich and also called “Head Toro”. Only about 1kg of this precious meat can be taken from even a very large fish, and it is only shared with regular, loyal customers.

Hohoniku” or cheek meat is taken from below the eye, seasoned, grilled and made into gun-kan rolls. The taste is enhanced in this part by grilling.

Kamatoro” is taken from behind the jaw. It is known as “shimofuri” or marbled meat. There are no veins in this part so the meat is soft and the marbling is more detailed than Ohtoro, so it is sticky and melts in your mouth. The balance of fat and sweetness in this part is unparalleled.

Chiai” is the part with the most veins, so it is a dark red color. It has a strong odor of blood and has multiple times the acidity of the lean meat, so it is not used as a sushi topping.

Chiai Gishi” is near the Chutoro and some say that it is the most delicious lean meat there is.

Wakaremi” is a precious part with very little meat found on the next to the dorsal fin. The part especially close to the dorsal fin is popular and called “Setoro” or back toro. The light taste is a combination of the deliciousness of both the lean meat and that won’t fill you up. However, this part is hard to get, even in high-quality tuna and is not available except to regular customers in almost all sushi restaurants.

If you are fortunate enough to get an opportunity to taste these , you can take it as proof that you have been accepted as a regular and loyal customer. It is difficult to distinguish these parts by appearance alone, so make sure you try them at a sushi restaurant you can trust. Just for your reference.


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Revision date: November 20, 2017