Imagine checking into a hotel in Japan.

You take the elevator.

Wait...

Where did 4 go?

Or perhaps you're visiting someone in the hospital and decide to bring a gift.

Four flowers?

Maybe choose five.

Why?

Because in Japan, certain numbers have associations that can make them feel...

a little unlucky.

These are sometimes called imikazu (忌み数)—numbers that are avoided because of superstition, wordplay, or cultural associations.

And the most famous one of all?

4.

Not because of mathematics.

Because of how it can sound.

What Does Imikazu (忌み数) Mean?

忌み数 (imikazu) refers to numbers regarded as unlucky or inappropriate in certain situations.

The word can be broken down as:

忌み (imi) = avoidance, taboo

数 (kazu) = number

So you can think of 忌み数 as:

numbers traditionally avoided because of negative associations.

Japan isn't unique in having unlucky numbers.

In many Western countries, 13 has a bad reputation.

In Japan, the numbers you'll hear about most often are:

4 and 9.

And the reason is deeply connected to the Japanese language.

Why Is 4 Unlucky in Japan?

The number four can be pronounced in Japanese as:

shi (し / 四).

Unfortunately...

there's another Japanese word pronounced shi:

死

which means:

death.

Same sound.

Very different meaning.

Because of this association, 4 can be avoided in situations where reminding someone of death would feel uncomfortable or inappropriate.

That's why Japanese people also commonly pronounce four as:

yon (よん).

Four isn't forbidden.

Japanese people use it every day.

But in certain situations...

shi is not exactly the association you want.

Why Is 9 Considered Unlucky?

Nine has a similar problem.

One pronunciation of 9 (九) is:

ku.

And 苦 (ku) can relate to:

suffering, hardship, or anguish.

So while 4 can evoke death...

9 can evoke suffering.

Again, this doesn't mean Japanese people spend their lives terrified of the number nine.

The association simply makes it undesirable in certain contexts.

Especially when someone is already sick or vulnerable.

Are 4 and 9 Avoided in Japanese Hospitals?

This is where imikazu becomes particularly interesting.

Because associations with death and suffering are especially undesirable around illness, some hospitals and medical facilities may avoid certain numbers in room numbering or other contexts.

Imagine being admitted to hospital and receiving:

Room 4.

If you're already familiar with the association between shi and death...

it may not feel particularly comforting.

The same idea can apply to 9 because of its association with suffering.

But this isn't a universal rule.

You'll absolutely still encounter 4 and 9 throughout Japan.

Think of it as a cultural tendency rather than:

“Japan doesn't use these numbers.”

Why Is 42 Especially Unlucky?

Now Japanese number superstition gets even more interesting.

Sometimes it's not one number.

It's a combination of numbers.

Take:

42.

Four can be read:

shi

Two can be read:

ni

Put them together:

shi-ni

That sounds like:

死に (shini)

which is associated with dying / death through the verb shinu (死ぬ), “to die.”

Not exactly the happiest number combination.

Because of this wordplay, 42 can carry an especially unpleasant association in some contexts.

What About the Number 49?

Another notorious combination is:

49.

Four:

shi

Nine:

ku

Together:

shiku.

This can evoke expressions connected with suffering and death, making 49 another number sometimes regarded as inauspicious.

Japanese superstition loves wordplay.

And once you understand how Japanese numbers can have multiple pronunciations...

you begin to see why.

What Is Goroawase?

To really understand Japanese number culture, it helps to know about:

goroawase (語呂合わせ).

Goroawase is Japanese wordplay that uses the different possible sounds associated with numbers to create words and phrases.

A number might be read in several different ways depending on whether you're drawing from Japanese readings, Sino-Japanese readings, or sound approximations.

That makes numbers surprisingly flexible.

Sometimes the result is unlucky.

But sometimes...

it's very lucky.

Or just funny.

Numbers can become names, dates, slogans, phone numbers, and memorable phrases.

So imikazu is part of a much larger Japanese fascination with the sounds hidden inside numbers.

Is 4 Always Avoided in Japan?

No.

This is important.

You shouldn't visit Japan expecting every building to jump directly from:

3 → 5.

The number 4 is completely normal in everyday Japanese life.

You'll see it on:

🚉 Train platforms

🏢 Buildings

📅 Calendars

💴 Prices

🏠 Addresses

📱 Phone numbers

It's the context that matters.

A number associated with death might feel more uncomfortable in a hospital than on a train platform.

And individual attitudes vary enormously.

Some people care.

Some barely think about it.

Some may follow the custom simply because...

why tempt fate?

Are There Unlucky Room Numbers in Japanese Hotels?

Sometimes.

You may encounter buildings, hotels, hospitals, or apartments where certain room or floor numbers are omitted.

But practices vary considerably.

It's similar to how some Western buildings omit the 13th floor.

The building obviously still has a floor between 12 and 14.

It just isn't...

called 13.

In Japan, 4 can occasionally receive similar treatment.

Different culture.

Same human idea:

Maybe we just won't put that number on the door.

Is 13 Unlucky in Japan Too?

Traditionally, 13 doesn't have the same central place in Japanese number superstition that it has in many Western cultures.

The stronger Japanese associations are with numbers such as 4 and 9 because they come directly from Japanese pronunciation and wordplay.

Of course, modern Japan is exposed to Western culture too.

So the idea of 13 being unlucky isn't exactly unknown.

But if you want to understand traditional Japanese imikazu...

start with 4 and 9.

Are Any Numbers Lucky in Japan?

Absolutely.

Japan doesn't only have unlucky numbers.

One particularly auspicious number is:

8 (八).

Look at the kanji:

八

The shape widens toward the bottom.

This is called suehirogari (末広がり)—the idea of something spreading or expanding toward the future.

Because of that visual symbolism, 8 is associated with prosperity, growth, and good fortune.

So while 4 may make some people hesitate...

8 has a much happier reputation.

Why Is 7 Lucky in Japan?

Seven also has many positive associations in Japanese culture.

There are:

Shichifukujin (七福神) — the Seven Lucky Gods.

Shichi-Go-San (七五三) — the traditional celebration for children aged seven, five, and three.

And the seventh day after a baby's birth traditionally has cultural significance as well.

Seven appears repeatedly in Japanese customs, religion, folklore, and celebrations.

So numbers in Japan aren't simply:

lucky or unlucky.

They're woven into language and tradition.

Does Japan Really Believe in Unlucky Numbers?

Some people do.

Some don't.

And many probably sit somewhere in between.

That's what makes cultural superstitions interesting.

You don't necessarily have to genuinely believe:

“Four will bring me bad luck.”

You might still avoid giving four items to someone in hospital because...

why give them something associated with death?

Traditions can survive even when literal belief fades.

It's a little like knocking on wood.

You may not truly believe the universe is listening.

But still...

knock knock.

Why Are Imikazu So Japanese?

Unlucky numbers exist around the world.

What makes Japanese imikazu particularly interesting is their close relationship with the Japanese language.

A perfectly ordinary number can suddenly acquire another meaning simply because of how it's pronounced.

4 → shi → death

9 → ku → suffering

And combinations can create even more wordplay.

It's a tiny reminder that understanding Japan sometimes requires more than translating words.

You have to hear them.

Because occasionally...

even the numbers are saying something.

Fun Facts About Imikazu

• Imikazu (忌み数) refers to numbers traditionally avoided because of unlucky associations.
• 4 (四) can be pronounced shi.
• Death (死) is also pronounced shi.
• Four can alternatively be pronounced yon.
• 9 (九) can be pronounced ku.
• 苦 (ku) is associated with suffering or hardship.
• Some hospitals and other facilities may avoid certain numbers.
• 42 can be associated with shini, evoking “death” or “dying.”
• 49 can also have negative associations through number wordplay.
• Avoidance of unlucky numbers depends heavily on context.
• Not every Japanese person is superstitious about numbers.
• Goroawase (語呂合わせ) uses number sounds to create Japanese wordplay.
• Number wordplay isn't always negative—it can also create lucky or humorous meanings.
• 8 (八) is considered auspicious because its shape widens toward the bottom.
• 7 has many positive cultural associations in Japan.
• Japan's unlucky-number traditions are sometimes compared with Western superstition surrounding 13.

Frequently Asked Questions

What does imikazu mean?

Imikazu (忌み数) refers to numbers considered unlucky or traditionally avoided because of cultural, linguistic, or superstitious associations.

What is the unluckiest number in Japan?

4 is probably the best-known unlucky number because one pronunciation, shi, sounds exactly like 死 (shi), meaning death.

Why is 4 unlucky in Japan?

The number 4 (四) can be pronounced shi, while 死 (shi) means death.

Why do Japanese people say yon instead of shi?

Both can be readings of the number four, but yon avoids the homophone with shi (死), meaning death. Which reading is natural also depends on the expression and context.

Why is 9 unlucky in Japan?

One reading of 9 (九) is ku, which shares its sound with 苦, associated with suffering and hardship.

Do Japanese hospitals skip room number 4?

Some facilities may avoid numbers associated with death or suffering, but this isn't a universal practice across Japan.

Is 42 unlucky in Japan?

It can be. The numbers can be read shi-ni, creating an association with shini and the Japanese verb for dying.

Is 49 unlucky in Japan?

49 can also be regarded as inauspicious because of wordplay involving the readings shi and ku.

Is 13 unlucky in Japan?

The Western superstition surrounding 13 is known in Japan, but traditionally 4 and 9 have much stronger Japanese linguistic associations.

What numbers are lucky in Japan?

7 and 8 both have positive cultural associations. Eight is especially associated with prosperity and expansion because of the widening shape of the kanji 八.

Do all Japanese people believe in unlucky numbers?

No. Attitudes vary. Some people take the superstition seriously, some follow the customs in particular situations, and others don't care about them at all.

🇯🇵 Keep Discovering Japan

If you enjoyed learning about imikazu (忌み数), you might also like discovering goroawase (語呂合わせ)—the playful Japanese tradition of turning numbers into words, names, jokes, and memorable phrases.

👋 Meet a JapPop Resident

Shadow Fox

不キツネー

He carries a giant scythe.

He dresses like the Grim Reaper.

And he absolutely loves unlucky things.

4? Perfect.

9? Even better. 💀

Shadow Fox lives for spooky surprises, but despite looking like bad luck has come to collect you...

somehow everyone ends up laughing. 😂

Maybe not everything that looks unlucky actually is.

👉 Meet Shadow Fox and discover more residents from the JapPop Universe.

🇯🇵 About JapPop

JapPop is a Japanese culture and character brand exploring the food, traditions, language, history, folklore, festivals, and everyday life of Japan.

Through easy-to-understand guides, original illustrations, and characters inspired by Japanese culture, JapPop helps curious people discover the stories behind Japan—from familiar traditions to the little things you might only notice when visiting.

Discover Japanese culture, one story at a time. 🇯🇵✨