A lot of holidays go unnoticed.
Take, for example, National Waffle Iron Day, or the Hug Holiday – both of which just so happen to occur on June 29th. In other words, you can eat enough waffles to induce a dopamine rush strong enough to get you through a day of unsolicited embraces.
Meanwhile, here in Japan, we won’t have to endure sugar-loading and awkward hugs.
Instead, June 29th in Japan commemorates tsukudani (佃煮), the food that kept Tokyo’s founding father alive.
Best Friend Dead, Long Road Ahead
In 1603, Tokugawa Ieyasu (徳川家康) became, indisputably, the most powerful man in Japan. Ieyasu was the founder and first shōgun of the Tokugawa Shogunate, whose hegemony would last for the next 200 years. His bloodline would rule over Japan from within the walls of Edo Castle (now the grounds of the modern Imperial Palace).
Two centuries of power and an everlasting impact on future generations aren’t the sort of thing one accomplishes thanks to pure dumb luck.
But, still, luck did play a big part.
See, Ieyasu was next on the kill list after his bestie Oda Nobunaga, the leading daimyō lord of pre-Edo era Japan, was forced to commit ritual suicide. That fateful night in 1582 went down in history as the Honnō-ji Incident (本能寺の変).
Word traveled fast to Osaka, where Ieyasu was at the time of the attack. Ieyasu and his escorts frantically hit the road to safety.
They were en route to their base territory in Mikawa (三河), in modern-day Aichi Prefecture. Then came more bad news. The same assassins who had forced Nobunaga’s death had an ambush waiting for Ieyasu down the path.
Ieyasu and his entourage were forced to head back the way they’d come. Bad luck had struck again.
They found themselves in front of the Kanzaki River. Without a boat, it was a dead end.
Out in the open, they were sitting ducks for the assassination squad.
Their chances for survival were quickly fading – and with them the chain of events that led to two centuries of Tokugawa rule.
What happened next spared Ieyasu’s life and set the course of history back on track.
Tsukuda Village rose in the center of the Kanzaki River. Its local villagers were skilled fishermen that had exactly what Ieyasu needed: boats and food.
The Hero History Books Don’t Teach
Mori Magoemon, village leader of Tsukuda, gifted a boat and ample supply of tsukudani (佃煮) to Ieyasu and his men.
Fish and seaweed, extensively boiled in soy sauce and sugar, transform into tsukudani–––a long-lasting food perfect for emergencies.
With a boat and ample supply of tsukudani, Ieyasu’s band made it to their Okazaki Castle in Mikawa.
Even after Ieyasu returned to safety, he did not forget the fishermen of Tsukuda.
In 1590, Ieyasu was on the rise to power. But he wasn’t going to cruise upward the ranks without completing ongaeshi (恩返し), the Japanese term for “returning a great favor.”
Ieyasu moved Tsukuda village leader Mori Magoemon, all seven members of his family, and thirty-three fishermen to Edo. In 1613, he gave them a special permit called gomensho (御免書). This gave exclusive access to all fishing areas in Edo to the Tsukuda fishermen, making them VIP fishers.
In 1624, tensions rose between the Tsukuda fishermen and local samurai. Some of the fishermen had been renting rooms in a samurai district; as commoners, however, the samurai did not take kindly to their upjumped housing location. The samurai instituted a ban on commoners, kicking the Tsukuda samurai out.
But Ieyasu came through with ongaeshi again.
The bakufu (幕府, the Tokugawa government) gave the Tsukuda fishermen ownership of tideland that rose above the Sumida River. This island, an area of more than 28 thousand square meters, came to be known as Tsukuda-jima (佃島).
The little island of fishermen thrived over many generations and grew to a community of 80 houses with more than 160 fishermen.
Edo Gone, Tsukudani Stays
The humble heroes from Osaka now had a second home in Tokyo. But they never forgot their roots. They blessed Tsukuda-jima with the gods of their hometown shrine, Sumiyoshi Jinja (住吉神社), which still stands in Tokyo today.
In fact, most of Tsukudajima is preserved to this day. The original landscape survived fires from the 1923 Great Kantō Earthquake and WW2 air raids. How? Residents were really good at putting out the fires with buckets of water.
That’s why we have tsukudani shops over 180 years old still in business today.
Marukyū (丸久), Ten’yasu (天安), and Tsukugen (佃源) are all located in Tsukuda district today. They each offer a variety of more than 10 tsukudani dishes.
But the demand for tsukudani has died out since the end of WW2, which brought dietary changes and refrigerators to Japan. People could get on without eating super salty and preservable fish.
The region that currently consumes the most tsukudani is far from Tsukuda-jima in Tokyo. Fukui Prefecture, located in Southern Japan, holds the record for most consumed tsukudani per household–––roughly a kilogram per year.
Despite the drop in demand, tsukudani continues to be produced not just in Tokyo but nationwide. Prominent spots include Shōdo Island in Kawaga Prefecture–––a beautiful area with white sand beaches that you would mistake for Okinawa. Another is Yaizu City in Shizuoka Prefecture, where they make tsukudani with tuna and bonito.
More Than Sushi
So, why does tsukudani deserve a holiday? Or your attention that could be spent on real news?
Well, it tells you just how narrow the outside world’s understanding of Japanese cuisine is. Think of fish in Japan, and how many people can up with more than sushi or sashimi?
But the sushi that you take for granted as the most Japanese dish isn’t even sushi in its original form.
The raw fish that comes on vinegar-soaked rice? Spoiled fish would’ve compelled Japanese peasants to lose their lunches in their fishing buckets.
For most of Japanese history where no refrigerators existed, fish was prepared so that it would last a long time, like tsukudani.
The first form of sushi was fermented sushi, or narezushi (熟鮓). It took more than a year for a piece of sushi to be ready to eat. Not the one minute it takes for the sushi conveyor belt to slide over your fatty tuna roll.
By all means, go for the conveyor belt sushi. It’s good.
But maybe also try out tsukudani. You might even receive a bit of that residual Ieyasu luck.
 漁民から全国へ広まった「佃煮」. ミツカン水の文化センター
 中央区の島物語・佃島. 中央区観光協会特派員ブログ
 佃煮の日（6月29日 記念日）. 雑学ネタ帳
 6月29日は「佃煮の日」について. 全国調理食品工業協同組合
 佃煮と「本能寺の変」の意外な関係とは？. ニッポン放送NEWS ONLINE
 【都市別】昆布の佃煮への支出額・消費量ランキグ. 食品データ館
 International Fishermen Day 2023: Theme, History, Quotes, Date. All World Day
 発祥の地・佃島の老舗で佃煮を味わおう. The Gate
 本能寺の変よりも前に、織田信長は何度も殺されかけていた！？. 刀剣ワールド
 Funazushi: The fermented predecessor of modern sushi. BBC Travel