Happy Monday! 👋
I hope your week is off to a great start.
Before we get into this email, quick question: how many unread books do you have sitting on your shelf right now? Be honest!
Maybe it's three. Maybe it's thirty. Maybe you've stopped counting altogether.
It turns out, there's a Japanese word for exactly that habit. And once you know it, you'll never look at your bookshelf the same way again.
Let's get into it!
Language: Japanese. "Tsundoku" (tsoon-DOH-koo)
Meaning: Tsundoku describes the act of buying books and letting them pile up, unread.
In English, we might say:
"My to-read pile is completely out of control."
"I keep buying books I haven't opened yet."
Japanese captures the whole habit in one word: Tsundoku. The buying, the stacking, the gentle guilt. All of it, in a single word.
Why it's fascinating:
The word blends two ideas:
tsunde oku (積んでおく): to stack things up and leave them for later
doku (読): to read
It first appeared in print around 1879 as a pun. And here's the thing: it carries no moral judgment. It just names the habit. Japanese culture has long valued books as objects worth owning, completely separate from the act of actually reading them.
In the 2010s, tsundoku went viral internationally after language blogs and Reddit discovered it. It was covered by the New York Times, the Guardian, and countless "untranslatable words" lists. The reason? People everywhere recognised themselves in it immediately.
A survey by the UK's National Literacy Trust found that over 50% of adults have an untouched "to-read" pile. So tsundoku isn't just a Japanese thing. Japan just got there first and gave it a name.
Example:
また本を買ってしまった。完全なツン読だ。
"I bought more books again. Classic tsundoku."
Ainu: Japan's Other Language
Most people think of Japan as a monolingual country. But long before Japanese spread across the islands, the Ainu people of Hokkaido had built an entire civilisation, along with a language that has no known relatives anywhere in the world.
Ainu is a language isolate. It belongs to no family. No confirmed ancestor. No confirmed cousins. Just itself.
At its peak, Ainu was spoken across Hokkaido, Sakhalin, and the Kuril Islands. Today, UNESCO classifies it as critically endangered. Fewer than 10 fluent native speakers remain, and nearly all of them are elderly.
The reasons are painfully familiar: Japanese-language schooling from the Meiji period onward steadily pushed Ainu out of public life. Children were encouraged, sometimes outright forced, to leave the language behind.
In 2019, Japan officially recognised the Ainu as an Indigenous people for the first time, and the Ainu Promotion Act gave the language legal standing. Preservation efforts are now underway. But with this few speakers left, documentation is a race against time.
Ainu is polysynthetic, meaning a single word can express what English needs an entire sentence to say. It encodes a completely different logic of thought. And it's almost gone.
You probably use Japanese words every day without knowing it.
The word "tycoon" comes from taikun (大君), meaning "great lord." American diplomats used it for the Shōgun in the 1850s, and it eventually crossed into English to mean any powerful business figure.
"Emoji" looks like it could be Italian or Spanish. It's not. It's entirely Japanese: e (絵) means picture, moji (文字) means character. A Japanese invention now used by billions of people every single day.
And "tsunami" comes from tsu (津, harbour) and nami (波, wave). It's now standard vocabulary across virtually every language on Earth.
Japanese has one of the most successful track records of exporting words into global use. Most people have no idea.
Join the Conversation
Are you a tsundoku collector? How many unread books are on your shelf right now? Hit reply and tell me. I read every single one.
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