What Is Nezumi Kozō (鼠小僧)? Japan’s Legendary Robin Hood

A thief sneaks into a wealthy samurai residence in the middle of the night.

He takes the money.

He disappears without a trace.

And according to legend, some of that money finds its way to the poor.

His name was Nezumi Kozō (鼠小僧) — one of Japan’s most famous outlaws from the Edo period.

He was a real thief.

But over time, his story grew into something much bigger.

A criminal became a folk hero — Japan’s own version of Robin Hood.

Let’s discover the story behind Nezumi Kozō.

Who Was Nezumi Kozō?

Nezumi Kozō (鼠小僧) was the nickname of Nakamura Jirōkichi (中村次郎吉), a real thief who lived in Edo — present-day Tokyo — during the early 19th century.

His nickname can be broken down as:

• 鼠 (nezumi) – mouse or rat
• 小僧 (kozō) – young boy, apprentice, or young servant

So Nezumi Kozō can roughly be understood as “Rat Kid” or “Rat Boy.”

It was a fitting nickname for someone famous for quietly slipping into heavily guarded residences and escaping with money.

What Did Nezumi Kozō Steal?

Nezumi Kozō became particularly famous for stealing from the residences of wealthy daimyō (大名) — powerful feudal lords — and samurai families.

These weren't ordinary houses.

Daimyō residences could be large compounds with servants, guards, gates, and walls.

Yet Nezumi Kozō reportedly managed to enter them repeatedly.

Rather than taking large objects that would be difficult to carry, he primarily targeted money.

This helped create his image as a clever little thief who could sneak into the homes of some of the most powerful people in Edo.

Did Nezumi Kozō Really Give Money to the Poor?

This is where history starts turning into legend.

Nezumi Kozō is often described as a Japanese version of Robin Hood:

Steal from the rich. Give to the poor.

It's a wonderful story.

But there is little historical evidence that he actually distributed his stolen money among poor people.

The Robin Hood image appears to have grown around him through storytelling and popular culture.

So the real Nezumi Kozō and the legendary Nezumi Kozō aren't necessarily the same person.

The real man was a thief.

The legend became a hero of ordinary people.

Why Did People Love Nezumi Kozō?

Part of Nezumi Kozō's popularity came from who he stole from.

Edo-period Japan had a strict social hierarchy, and samurai belonged to the ruling warrior class.

Nezumi Kozō was an ordinary man who repeatedly managed to outsmart wealthy and powerful samurai households.

That made for a very satisfying story.

Instead of imagining him simply as a criminal, people could see him as the clever little underdog challenging those above him.

And the more his story was retold, the more heroic he became.

How Was Nezumi Kozō Caught?

Nezumi Kozō's luck eventually ran out.

He was captured in 1832.

Authorities discovered that he had committed numerous thefts, and he was sentenced to death.

He was publicly executed in Edo.

Normally, that might have been the end of the story.

For Nezumi Kozō, it was almost the beginning.

After his death, stories about the mysterious thief continued to spread.

Where Is Nezumi Kozō Buried?

Nezumi Kozō is traditionally associated with a grave at Ekōin (回向院) in Tokyo's Ryōgoku area.

And his grave developed an unusual tradition of its own.

Visitors have long scraped or chipped small pieces from a stone associated with his grave for good luck.

Why?

Because Nezumi Kozō was famous for repeatedly avoiding capture.

Over time, people began connecting his ability to escape with their own hopes of avoiding failure or getting through difficult situations.

Students and people facing important challenges have been among those associated with the custom.

A man once chased by the authorities eventually became someone people visited for luck.

That's quite a transformation.

Was Nezumi Kozō a Hero or a Criminal?

Historically?

He was a thief.

But folklore doesn't always remember people exactly as they were.

It remembers the story people found meaningful.

For ordinary people, Nezumi Kozō represented the small guy outsmarting the powerful.

The idea that he gave his stolen money to the poor made that story even better.

Whether or not the Robin Hood part was true, it became an important part of his legend.

And almost 200 years later, Japan still remembers the little “rat” who dared to sneak into the houses of the powerful.

Frequently Asked Questions

Who was Nezumi Kozō?

Nezumi Kozō was the nickname of Nakamura Jirōkichi, a famous thief who operated in Edo, present-day Tokyo, during the early 19th century.

What does Nezumi Kozō mean?

Nezumi (鼠) means mouse or rat, while kozō (小僧) can refer to a young boy, apprentice, or servant. The nickname is often translated loosely as “Rat Boy” or “Rat Kid.”

Was Nezumi Kozō a real person?

Yes.

Nezumi Kozō was based on the real thief Nakamura Jirōkichi.

Was Nezumi Kozō Japan's Robin Hood?

He is often compared to Robin Hood because later stories portrayed him as stealing from wealthy samurai and helping poor people.

However, there is little historical evidence that he actually distributed his stolen money to the poor.

What did Nezumi Kozō steal?

He became famous for stealing money from wealthy samurai and daimyō residences in Edo.

When did Nezumi Kozō die?

Nezumi Kozō was captured and executed in 1832.

Where is Nezumi Kozō's grave?

His grave is traditionally associated with Ekōin Temple in Ryōgoku, Tokyo.

Why is Nezumi Kozō famous today?

His real crimes evolved into a popular legend about a clever underdog who challenged the wealthy and powerful. His story has appeared in Japanese theater, literature, film, television, and popular culture.

🇯🇵 Keep Discovering Japan

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ネズミ小僧

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This quick-footed little thief sneaks through the night, always looking out for those who need a helping hand.

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a little kindness is worth more than a bag full of gold.

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🇯🇵 About JapPop

At JapPop, we celebrate Japanese culture through playful illustrations, original characters, and stories inspired by the traditions, foods, folklore, and everyday moments that make Japan unique.

From educational articles to original characters and wearable art, our mission is to help people around the world discover Japan—one smile at a time.