A lifetime of carefully selecting the finest tuna has given Yukitaka Yamaguchi a superpower — he can tell where a fish has come from simply by its taste.
"Canadian tuna eat herring so there's a certain smell to the taste of that tuna," he explains.
Japanese tuna, on the other hand, has a "clean" taste and aroma due to the pure waters of Japan's archipelago and its unique local ecosystem.
"Small fish can grow peacefully and stress-free," he says. "This makes the small fish in Japan very stress-free and tasty. That's why Japanese tuna is the one and only."
In Tokyo's Toyosu fish market, the world's largest, Yamaguchi is known as the "Tuna King".
His finely tuned palette is highly sought after in Tokyo, where food culture has become an obsession.
Tuna is the country's most prized fish, with a single fish selling for $2.2 million at the first auction of this year.
Not only does Yamaguchi source the best produce but he will only sell to those chefs he knows and respects.
If a fish fails to meet his expectations, he'll quickly discard it as a costly loss.
"If it's not worth it, we can't keep it," he says. "I always say it doesn't matter how much it costs me."
And as for sleep? He barely gets four hours a night, with his day starting at about 2am.
But Yukitaka Yamaguchi, 62, is showing no signs of slowing down. This is much more than a job.
"I'm always thinking of tuna, whether I'm awake or asleep," he says. "I dream about tuna all year round."
It's this level of dedication that has earned Tokyo the reputation as the culinary capital of the world, with far more Michelin Star restaurants than its nearest rival, Paris.
For some chefs, the reason for the city's success lies in Japan's unique "shokunin" spirit, which translates to craftsman.
That is, a dedication to perfecting a dish, even if it takes a lifetime.
For others, it's the Japanese who have a picky palette, and a unique appreciation of the all-important umami flavour, which drives chefs to make the best.
Whatever the reason, one thing is for sure: record numbers of tourists are flocking to Tokyo, including nearly a million Australians last year, eager for a taste.
The art of doing one thing well
Perusing the streets of Tokyo, you'll notice many restaurants have a limited menu. In fact, many specialise in just one dish.
This is a key reason for Tokyo's success: doing one thing and perfecting it.
It's certainty true for Nodaiwa, a restaurant tucked away in the upmarket enclave of Abazu Juban. For the past 200 years, it's only served the eel delicacy called unagi.
Nowadays, it's run by fifth-generation owner and living legend, Kanejiro Kanemoto.
"In the old days, the customers who came to the restaurant would have been samurai warriors," the 96-year-old explains.
At 5am the craftsmanship is on full display as a team of chefs work their way through some 600 slippery eels for the lunchtime crowd.
"It takes three years [to master] skewering," grandson and trainee chef Entaro Kanemoto says. "Eight years for splitting the eel and a lifetime for grilling."
But cooking eel isn't the key to this restaurant's success. The secret is in the sauce.
"The life of an eel restaurant depends on the sauce," Kanejiro Kanemoto says.
It's such a prized possession, Kanejiro Kanemoto had to protect it in makeshift bomb bunkers during the World War II.
"I dug an air-raid shelter as hard as I could to put the sauce in it," he recalls. "My parents had a hard time trying to find a way to protect the sauce from the air raids of the war."
The sauce is a blend of mirin and soy sauce, plus a few secrets that he won't share.
It may seem like a simple recipe, but it's taken a lifetime to master as well as true dedication to the "Shokunin spirit".
"You won't understand in your 20s or your 30s," he explains. "It's not until you're 40s or 50s that you understand the subtle taste of that sauce. It took me decades to get to this point."
The quest for the perfect noodle
In Tokyo, you don't need to explore the rich end of town to find a Michelin Star restaurant.
Just outside the city's main wards is the award-winning Tomita, run by the charismatic Osamu Tomita.
Here, a bowl of his world-famous ramen costs less than $20.
"I want customers to be more and more happy," Tomita says. "I want to serve more and more delicious ramen to our customers. That's all I want."
The prized dish, tsukemen, is a little bit different to your classic ramen.
Here, rather than a big bowl of soup, customers are served thick noodles that they dip into a rich, brothy sauce made of fish and pork.
"There are many types of ramen — shoyu (soy sauce), miso, salt, tsukemen and tonkotsu (pork). There are so many variations that even if I ate them every day, I wouldn't be able to catch up."
Osamu Tomita is a "ramen head", a common term for those absolutely devoted to the dish.
On the wall of his restaurant is a large photo of the pioneer of tsukemen ramen, chef Kazuo Yamagishi, along with a range of awards Tomita has won over the years.
Now, after decades of perfecting his own recipe, customers come from all over the world to try his ramen.
While the deep rich broth is a stand-out, what consumes Tomita is the quest for the perfect noodle.
"In the past, for ramen, the soup was the most important thing and the noodles were not so important," he explains.
"But in the last 10 or 20 years, noodles have been getting more and more attention, and especially for tsukemen. I personally think the noodles are more important than the soup."
A decade of mixing various flour combinations has got him to this point: a noodle that has a firmness that offers some resistance without tiring the customer's mouth.
It's simply delicious. But don't call it perfect.
"I still have a long way to go," he says.
The science of a superior palette
It's only normal for chefs to proudly proclaim their dishes and produce are of the highest standard.
But what if there was scientific evidence to back up the superiority of Japanese cuisine?
Flavour scientist Ryuichi Suzuki, of flavour testing company Oissy, has examined the very basis of Japanese food and believes the answer boils down to the flavour of umami.
"Japanese customers are very picky, so Japanese restaurant chefs are trained very hard," he says.
He's even written a book about it, aptly called Japanese people have the best sense of taste in the world.
It's a claim he says is backed by science.
Umami is the fifth flavour humans can detect, along with sweet, salty, sour and bitter.
It's often described as a savoury, moreish and meaty flavour.
With the help of a small machine, Suzuki can detect the level of each flavour in food.
"Taste buds inside your tongue tell you whether food is sweet, salty, sour, bitter or umami," he explains.
Umami is a Japanese discovery, identified in 1908 by chemist Kikunae Ikeda.
It was long dismissed as simply a flavour somewhere in between salt and sweet, but it is now widely accepted as its own unique flavour.
While bone broth and parmesan cheese are widely credited for being full of umami, a number of essential Japanese ingredients are also packed with it.
Seaweed and dried fish are key examples.
And a lifetime of eating umami-rich foods has given Japanese people a better ability to detect umami flavour, Suzuki argues.
"Our taste sensation has become more sensitive," he says.
To test his theory, Suzuki got 100 locals and 100 foreigners to taste water that had been contaminated with one of the flavour profiles.
The Japanese were able to correctly identify the flavours 80 per cent of the time, the foreigners just 60 per cent.
"Japanese have superior taste than foreigners," he concluded. And that, he says, is what's laid the foundations for Tokyo's superior culinary scene.
Sushi perfection is a life's work
Back at the Toyosu fish market, Yukitaka Yamaguchi is meeting with one of his favourite customers, rising sushi star Mei Kogho.
The pair talk about the latest catch as sushi is served for the staff to enjoy.
"I want to be the person who eats more sushi than anyone else," Kogho explains. "The more I face it, the more ideas I get."
Kogho's eight-seat restaurant, Sushi Meino, is in the upmarket neighbourhood of Azabu Juban.
It's booked out for months at a time — a remarkable feat in an industry that traditionally looks down on female chefs.
"I had to work harder than the men," she says. "The technical side and also the care and attention that only a woman can give."
What makes her stand out? Her pinpoint palette, of course.
"When I first met her, I was surprised by her perfect sense of taste," Yamaguchi explains. "As a craftsman, what is important is that she has a perfect palate."
Japanese cooking is often more paired back than other cuisines, meaning the quality of each ingredient is crucial.
White rice, for example, is often served plain, and not covered in flavourings or sauces.
This, it is argued, is a key reason why Japanese people are renowned for having more sensitive tastes.
In sushi, there is little room to hide.
"The fishermen take care of the fish when they catch them, and they devote their lives to catching fish," she explains.
"The intermediate wholesalers devote their lives to make sure that the fish is delivered to the right people and in good condition. And then it is delivered to my restaurant.
"I devote my life to it, to not let all that dedication go to waste."
It's a rationale Yukitaka Yamaguchi strongly concurs with.
"The ability to produce such wonderful things is the soul of the Japanese people or, as we often say in cooking, 'the battle without an end' or 'the spirit of no compromise'," he says.
"The Japanese have such a spirit, which happens to be concentrated in Tokyo."
Watch Tasting Tokyo tonight on Foreign Correspondent at 8pm on ABC TV and ABC iview.
