I was on the Shinkansen bullet train and roaring north toward the Japan Sea at 125 miles per hour when I passed through the wormhole in space-time. The wormhole was on the far end of a long, unlit tunnel. Three-quarters of an hour earlier, in the midst of a sunny winter’s day, I’d boarded the train at the loud, insanely complex and many-leveled Tokyo main station, accompanied by my friend Bob Sliwa. We were bound for the coastal town of Kanazawa, sometimes known as the hidden pearl of the Japan Sea and famed for the freshness and variety of its fish-based cuisine.

The trip there last winter was to be the climax of my weeklong attempt to find the hidden culinary truth of Japan, beyond the reach of guidebooks or the well-intentioned efforts of such celebrity investigators as Anthony Bourdain. My secret weapon in this was Bob himself, a man embedded in Japan for 30 years, deeply conversant in the ways and cuisines of the country and, by great good fortune, my college roommate.

We exited the tunnel into a crash of white light. On the far side was a winterscape of deep snow, mountain vistas and blowing wind. The day we’d been traveling through until then had been dry and mild, and the sudden atmospheric shift made it seem that we might, in fact, have just rocketed through a rift in space-time. Bob, stroking his goatee, laughed out loud at my confusion.

“We were climbing in the dark in that tunnel the whole time — didn’t you feel your ears pop?” he asked. “What you see here is the result of the steady wind blowing off the Japan Sea from China, picking up the moisture of the ocean along the way and throwing it against the mountains as snow — and lots of it. Think of the Continental Divide, Japan-style.”

I lowered my eyes from the Alpine visuals and back to my notes on the previous days’ eating and drinking. The pages, which were thick with arrows and exclamation points, seemed only to get more densely crosshatched as time went on, and for good reason. The dozen or so meals I’d had in Tokyo had been a marvel of consistent variation, ringing fluid changes of texture and flavor on those three little words that define the cuisine of this island nation at its heart: iso no aji, or “tastes like ocean spray.”

By agreement, the majority of places Bob and I had gone to so far were chosen to illustrate the point that the most creative cooking in Japan is no longer being done in A-list restaurants. Those places, which continue to serve up superb food, belong to the days when the country was still riding high atop the mighty economic surge that carried it from the ashes of World War II all the way to the forefront of the global market. They’re relics of the time when the Japanese, so expert at mimicry, sent their best young chefs to the high-end restaurants of France and Italy where their work ethic ensured them a rapid rise up the kitchen ladder, and upon their return, the creation of perfect interpretations of their previous employers’ cuisine.

It’s no accident that Tokyo has the highest number of Michelin-starred restaurants of any city in the world. But rather than sampling the wares of these warhorses, I’d arrived to try the second culinary wave, a quiet in-house revolution that is afoot all over the country. Driven by chefs mostly in their late 20s and early 30s, its inspiration was the collapse of that same economic surge in the early 1990s, followed by the now famous stagnation or “20 lost years,” as it’s referred to in the foreign press. As the country entered a period of soul-searching, these young chefs took the opportunity to throw off what Bob calls the “legacy exoskeleton” of manners and slavish obedience to groupthink and instead to begin advancing the cause of native ingredients, prepared with great care and what seems at times almost freakish originality.

Exhibit A: the plate of smoked salted cod roe sprinkled with red chile pepper flakes at a restaurant called N-1155 in the hip, hilly Tokyo neighborhood of Nakameguro. The smoking and salting produced a deliciously bespoke version of fish jerky, whose peppery marine tang married perfectly with a chilled glass of sauvignon blanc.

Exhibits B and C: a flash-cold-smoked sea perch sashimi, and a bagna cauda, both served at the same restaurant. Flash cold smoking, done in the kitchen just before plating, imparts a tangy, cooked woodland savor to the raw flesh of the fish that makes for a delicious cognitive dissonance in the mouth. The bagna cauda was upgraded by having its oil mostly replaced with cream, creating a rich bath into which produce from the restaurant’s own farm in southern Japan — thin-cut yellow carrot, mustard green, lotus root and kohlrabi — was dipped and then removed, leaving its bright, vegetal essences enrobed in unctuous garlic.

The next day, a few blocks away, it was the turn of a place called Harbor Bar. Modeled vaguely on a Venetian wine bar and boasting fish from the Sanriku Coast region of northern Japan, the tiny restaurant has a cheerfully casual D.I.Y. atmosphere that channels Bushwick. But there’s nothing casual about the food in the least.

The opener was a plate of super-fresh scallop sashimi, enlivened with a ginger sauce whose citrus notes gave the dish the feel of a mollusk ceviche. This was followed up by a serving of raw botan shrimp — as large as langoustines — which arrived paired with a spicy rémoulade of cured carrots. While we ate, Bob and I continued to catch up. Unusually for a Westerner who has been living long-term in Japan, he’s lost none of his youthful enthusiasm and manifests the same manic glee he once did as a jazz-mad, art-crazed undergraduate.

“Some people live here and want to be Japanese,” he said. “I didn’t. Not only is it impossible, but I don’t want to be treated the way Japanese treat themselves. I love Japan, but I sell myself as a foreigner who’s willing to break the rules and say what’s wrong.”

“And what is wrong?” I asked.

Bob, who works in Japan as an industrial designer, rubbed his hand over his shaved skull and said: “Two words define Japanese culture. One is ‘monozukuri,’ or ‘the Japanese way of making things.’ The other is ‘omotenashi,’ or ‘the Japanese way of hospitality.’ If the country rebuilt itself into such a buff economic specimen after World War II, it did so partly out of its belief in the superiority of both of these things to any other country’s. But then the bubble economy burst, the 21st century happened, and the country lost its way. I call it a nationwide case of the rope-a-dope. Whole industrial sectors have fallen asleep. Remember the Walkman? How’s that working out for you, Sony?”

Before I could answer the rhetorical question, my attention was distracted by the arrival of something called an iwagaki rock oyster.

Ah, that oyster. It was the largest bivalve I’ve ever seen, with a shell approximately the size and shape of my foot. “You freeze it while alive and then slow-cook it at low temperatures,” the waiter explained, bowing. “That makes the umami come out.” The monster was dressed in a brightly acid dill-based mignonette and disproved the axiom that larger versions of anything taste worse: It was a briny, exquisite splash of sea in the mouth.

I was still finishing it when the owner of the restaurant, alerted by my exclamations of joy, came over to talk. His name was Akira Matsuoka and he’s part of a restaurant consortium that oversees several venues in Tokyo. Rail thin, with high cheekbones, black jeans and alt-rock facial hair, he answered my question as to how he invents his dishes by explaining: “My partners and I think of ourselves as a food think tank. We don’t care about Michelin rankings. First we come up with the concept, and then we invent the dishes to fit it, sometimes collectively and sometimes individually. Rather than a star chef, we make the food the star.” He smiled and circled a finger in the air to indicate the small space crammed with diners. “And it seems to be working.”

Over the next few days, the culinary wizardry of Tokyo chefs remained unflagging. Yet, of all the entrees and appetizers I tried (the rice paper tubes of crab flash-fried so that the crunchy, starchy surface held a core of molten raw crustacean; the cod ovaries baked in Gorgonzola that scattered delicious marine bursts of garlic across the palate; the tiny fish called an ayu, or “sweet fish,” which is fermented in the dregs of sake for three years to make the bones grow edibly soft) — all of it, no matter how odd, gross or wonderful, would pale next to the one dish that remained dangling, like the holy grail, just out of reach. People spoke of it as the greatest white-fleshed sashimi in the world.

Back on the train, I heard Bob say, “We’re almost here,” and I slowly raised my eyes from my notebook. The fish was the legendary kanburi, or winter yellowtail, which abounds in the waters off Kanazawa, and after a couple of hours on the train, we were finally sliding into Kanazawa Station.

But before food, a drink. Several, actually. Drinking in Japan is a crucial social and professional lubricant in a country where ritualized courtesies can easily harden into walls, and Bob, a teetotaler in college, had successfully adapted. Kanazawa, like most Japanese cities of a decent size, has a distinct “drinking district,” honeycombed with tiny bars, and not long after checking in to our hotel, we found ourselves in a stand-up bar called Choikichi.

Stand-up means exactly what it sounds like, and the long counter of this former ice cream parlor was crowded on a late afternoon with regulars watching sumo wrestling on television. As titans clashed thunderously on the screen above us, the locals chatted happily with one another, and I had the sense of having wandered into a tiny Japanese analogue of Cheers, the famously chummy bar “where everybody knows your name.” We ate edamame and delicious rakkyo (pickled onions) and drank a fairly common but tasty sake.

Bob, a habitué of these places, was welcomed everywhere we went with shouts. The shouts were particularly loud later that night at a bar named, hilariously, Pub Dylan (as in Bob). There I was served a very expensive sake called Dassai, whose cool, perfect balance gave me the impression of drinking a dipperful of outer space. It was also at this place that Bob (my friend) brought down the house by correctly identifying the Japanese rock band playing on the big-screen TV as the Atomic Bomb Masturbation.

After a quick, delicious tempura dinner I returned to my dwarf hotel room, only moderately worse for alcoholic wear, and asked myself the obvious question: Is Japan the most food-crazed nation on earth? Evidence for “yes” is pretty thick on the ground. Tokyo has a staggering 80,000 restaurants, as opposed to the 15,000 of New York or the 6,000 of London. But more to the point: Where else on the planet would a country’s biggest boy band have its own cooking show? What other nation would stage a televised competition in which they brought in challengers to try to better a master sushi chef’s technique and scanned the resulting sushi pieces with an MRI to compare the ratio of rice to air? What other place could possibly, under any circumstances, have invented the operatic and off-the-wall “Battle of the Iron Chef”?

The very next day, as if in answer to these questions, Japan served me the best seafood meal of my life. It did so at a small, easily missed, relatively modest-looking restaurant called Yamashita.

Yamashita is on no foreigner’s must-see lists, and there wasn’t an English language word in sight. But the restaurant, located by Bob, is a temple of sorts where the eponymous owner and chef Mitsuo Yamashita is referred to by his employees as the Master, and boss and staff work as one to pluck the freshest, purest products from the nearby ocean and put them on your plate with minimal interference.

The meal began with a pictorially perfect tray of amuse bouches: thin-cut strips of yellowtail stomach dressed in a vinegar-miso sauce, which tasted smoked though they weren’t, along with a small pile of herrings fermented in the dregs of sake, and a handful of fresh snap peas, each dabbed with tiny blobs of black sesame pesto.

A sake, painstakingly engineered by Mr. Yamashita in consultation with local brewers, partnered these refined salty nibbles perfectly. But all this was a mere prelude to that moment when a waitress, smiling, brought in plates heaped high with the prized kanburi sashimi.

Why has this fish been elevated to the very top spot among sashimi lovers? Because kanburi uniquely fuses two qualities that are almost never found in the same animal. Take maguro, the tuna whose sashimi is most recognizable to Americans. There’s the red meat, or akami, version, with its firm texture and relatively mild flavor, and the pinker version known as otoro that is filled with delicious oils and fats. The problem is that the tasty otoro has a crumbly, falling-apart texture in the mouth likened disdainfully by Bob to “eating sashimi marshmallows.” Because texture, along with temperature and flavor, are part of the “mouth moment” of Japanese cuisine, the challenge is to find a firm fish that is also rich in oil.

Enter kanburi, which for that brief, miraculous period every winter, is both those things. The fish, in thick slabs, now lay fanned out on the plate before me, glistening with oil — oil that had leached out of it because the Master had intentionally let the fish “rest,” or cure for a day or so. Mind you, fish oil like this has nothing “fishy” about it. The kanburi was silky, pliant, yielding and tasted of a distilled, superclean essence of the sea. It seemed to exemplify everything that was best about Japanese cuisine, and mouthful by mouthful it put me into a kind of trance.

Suddenly the Master poked his head in again and barked some machine-gun Japanese at Bob, who translated it with a single word: squid. It was being offered as our next course, and there was no question of not taking it. One would as soon have refused an audience with the pope.

This would turn out to be something called “spear squid.” Freshly caught and still alive in the kitchen, it was killed, masterfully julienned and brought to the table as sashimi, along with a sauce made of fermented bonito guts, a condiment of pickled wild wasabi flowers, a heated stone and some stern admonitions from the Master as to exactly how to cook the squid — barely — and what the precise protocol was for eating it. Dishes like this belong to a category known for its hazawari, or “tooth feel,” and produce a dazzling mix of ocean flavor notes while offering an old-fashioned popcorn-like crunch in the mouth.

By the end of such a meal, something has happened to you, something close to the psychic euphoria produced by yoga or meditation. You’ve entered a zone of food satori, mystically zonked by the punch of a culture that has been perfecting its culinary subtleties for thousands of years. What to do?

After an elaborately choreographed goodbye, we took a digestive stroll in the seaside air, passing through the gaudy Kanazawa downtown with its Ginza-style flashing lights, its kuru kuru (conveyor belt) sushi restaurants (Japanese is rich in onomatopoetic words, and “kuru kuru” is the sound of a conveyor belt; say it fast and you’ll understand), its knickknack shops, bars and omnipresent FamilyMart convenience stores.

Our destination was the beautiful old wood-fronted part of town called Higasha Chaya-Gai. (Kanazawa shares with Kyoto the distinction of being one of the few large Japanese cities not bombed by the Allies during World War II). There, we entered a sleekly minimalist bar called Teriha and seated ourselves among the drinkers, conscious that it was our last evening out.

I had spent a full week living inside a kind of tone poem of fish and alcohol, enriched by unflagging conversation with a dear old friend. But a vague perception had been weighing on me constantly during the trip, and suddenly, in the dark bar, that perception sharpened into words: I’ve never been to so foreign a place before that felt so deeply familiar.

Differently from an Asian country like India, where I’ve also spent time, the social iconography of Japan is profoundly recognizable to an American. Despite the culture’s insularity and remoteness from us, the Japanese often dress and style themselves in a way that clearly states their social membership in categories of rocker, matron, intellectual, etc., and these identities can be easily “read” by a tourist from the United States. This fact, a product of the longstanding symbiotic relationship between the countries, produces a visual halo effect, in which one is always observing roles and mores on several levels at once. Exhausting on the one hand, it’s endlessly, compulsively fascinating on the other.

Back in the bar, the lights suddenly dimmed further, and the conversations ceased. Rain started to fall, visible out the windows. Shrouded in darkness at the end of the bar, the owner, an ex-geisha named Yaeko Yoshigawa, began playing a flute. It was a bamboo flute called a shinobue, much used in Noh and Kabuki theater music and part of the essential “kit” of the geisha. The slow, wavering tones, played without obvious melody but filled with richness, lack the forward propulsive quality of Western music. Instead, individual notes are held until they’re mere wisps of sound, acoustic vapor.

For several minutes, quietly, the flute music continued, threading the air in the darkness. It wavered, seemed about to stop and then, surprisingly, went on, moving forward without resolution, a little bit like the beautiful, perplexing country of Japan itself, whose mix of ceremonial gravity and hidden culinary wonders had given me a week of the very best eating of my life. There was a pause that extended until we could hear the rain pattering on the roof and a single last note, after which Ms. Yoshigawa removed the flute from her mouth with a bow. The recital was finished. The tone poem was over. In the semi-darkness, Bob raised his glass in a last toast. It was time to go home.

If You Go

Where to Stay

This particular trip was dedicated to eating, not lodging. In both Kanazawa and Tokyo there are abundant “business hotels,” found under that term on the Internet, where for usually less than $100 a night, or 11,390 yen at 114 yen to the dollar, one sleeps in a luxuriously appointed room the size of a large refrigerator. These are typically squeaky clean and have all modern conveniences, including, often, a washer-dryer and, incredibly, a pants press.

Where to Eat

Tokyo

N-1155, 1-1-55 Nakameguro, Meguro, Tokyo; 81-3-3760-1001.

A beautiful wood-paneled restaurant in one of the hipper districts of Tokyo that serves innovative, exquisitely prepared seasonal food. Much of the produce is from the restaurant’s own organic farm in southern Japan. An English-language menu is a plus. Dinner and drinks start at about 5,000 yen.

Harbor Bar (Minatomachi Baru), 3-7-8 Kamimeguro, Meguro, Tokyo; 81-3-5869-5806.

Hipster interiors and a crowd right out of Bushwick fill up this small, very tasty seafood shop. The place is modeled loosely on a Venetian fish restaurant and has a decent Italian wine selection, but the superfresh and very creative dishes are straight from the Sanriku Coast, north of Tokyo. Dinner and drinks from about 4,000 yen on up.

Kanazawa

Yamashita Restaurant, 2-23-5 Katamachi, Kanazawa, Ishikawa; 81-76-223-1461.

This world-class fish mecca is unostentatiously small and bare. Its stern, somewhat forbidding owner runs a very tight ship, and no English is spoken. But animated pointing at display cases will probably do the trick. Dinner and drinks, about 4,000 yen.

Teriha Restaurant and Bar, 1-24-7 Higashiyama, Kanazawa, Ishikawa; 81-76-253-3791.

Located in the historic wood-fronted district of the city, this wine bar with its beautiful, minimalist interior tends to fill up fast with the local A-list crowd. The owner, a former geisha, speaks some English. If you beg her for a shinobue (flute) recital, she may oblige. Drinks begin at 500 yen.

Pub Dylan, 3-25 Katamachi, Kanazawa, Ishikawa; 81-76-222-0322.

This small, friendly, deeply atmospheric watering hole is found in the city’s Shintenchi bar quarter. A rowdy crowd tends to form by late evening, and chatting is encouraged in whatever language you happen to speak. The Dassai sake (about 9,110 yen a glass) is out of this world. Other drinks begin at about 500 yen. Cash only.

Choikichi, 2-8-18 Katamachi, Kanazawa, Ishikawa; 81-76-261-4900.

This is old-school working-class Japan. A single standing-only counter, jars of pickled bar food and local workers sighing over sumo wrestling on TV. The owner is often referred to as Mom (in Japanese, of course) by the clientele. No English spoken. Snacks and drinks start at 200 and 300 yen respectively.