Mosquito Coils / Screw Removal Tools

"Japan's Top Inventions"

The behind-the-scenes tales of hit products and creations from Japan.

This is "Japan's Top Inventions."

This time, a repellent for those blood-sucking mosquitoes!

We discover the unusual inspiration behind this coiled invention.

Meanwhile, check out this screw.

It's been stripped, so a screwdriver is no use.

We'll introduce a top invention that makes it easy to remove!

Hello, welcome to "Japan's Top Inventions."

I'm your host, Jason Danielson.

In the first half of our show, we take you "Behind the Creation."

Today's topic is this.

Mosquito coils, a common sight during the summer in Japan for over 130 years.

Light the coil of incense, and watch the smoke rise.

The insecticide in the smoke knocks out any nearby mosquitoes.

These coils are used around the world,

offering protection against mosquito-borne diseases

like malaria or dengue fever.

How were they invented? It all started with a certain white flower.

Arida, a city in Wakayama Prefecture, west Japan.

It's home to a statue of a certain individual.

Ueyama Eiichiro.

Some 130 years ago, he invented mosquito coils.

His birth home, which still stands,

is now home to important artifacts from that time.

This is the machine used for creating mosquito coils.

Here, kneaded materials were pressed into stick form.

This wooden mold was used to fix prototype coils into shape.

This is where that iconic spiral, still used today, was born.

Our story begins in 1885.

With its warm climate,

Wakayama was known as a large producer of "mikan" oranges.

Ueyama Eiichiro was the owner of a long-running mikan farm.

He founded a firm to export mikan abroad.

His idea was to sell his fruits worldwide.

Ueyama's great-grandson, Ueyama Hisashi,

works as an executive at a maker of insect repellent.

He describes his great-grandfather's time.

It was the Meiji Period.

Japan had opened up and was determined to start its own industries,

and even export, to keep up with the West.

Since he was a mikan farmer, he decided to join in by exporting his own mikan.

That was his goal.

One day, Ueyama had a chance to speak

with the president of an American plant company.

Ueyama gave him a mikan sapling.

In return, he received seeds for a flower not seen in Japan.

Pyrethrum.

The flower is native to what is now Serbia, in Europe.

Its seeds contain a compound that acts as a natural insect repellent.

Pyrethrin, the compound that kills insects, comes out in seed form.

In Europe, it was mostly used as flea powder.

It had been gaining attention for some time.

Ueyama decided to start cultivating these flowers in Japan.

A valuable document he created himself remains.

A guide to growing the flowers.

It's said he traveled Japan giving lectures with this guide,

appealing to farmers nationwide.

Thereafter, cultivation expanded,

and its seeds were used as raw material to produce flea powder.

Its effectiveness led to its quick popularity.

One day, Ueyama ran into a farmer he knew on the street.

They started talking about the flea powder.

"It's working well," Ueyama was told.

"How about making a mosquito repellent next?"

To make rice, fields are flooded with water,

then seedlings are planted.

In summer, mosquitoes arrive in force.

Bites aren't just itchy,

they can spread a variety of diseases, leading to sickness.

Ueyama thought to himself,

creating a mosquito repellent would help not only farmers

but anyone worried about disease.

What's the insect that causes the most stress in Japan?

Even today, the answer is the same. Mosquitoes.

So he wondered if he could make something effective against them.

With that, Ueyama had his idea for a new product.

He quickly gathered some pyrethrum, as the raw material.

How to repel mosquitoes with these flowers?

Ueyama thought of "kayaribi," mosquito-repelling smoke,

long used in Japan.

Mugwort and other leaves were burned, releasing smoke to repel mosquitoes.

With this as inspiration, Ueyama turned to "hibachi,"

a kind of Japanese heater fueled by charcoal.

If he burned powder from the pyrethrum in one, would the smoke repel mosquitoes?

He tried it out, and...

A mosquito fell to the ground.

It worked!

I imagine he was thrilled. A triumphant feeling.

No one had seen that before.

Old mosquito smoke only chased them away. It didn't kill them.

But his did.

It must have been a terrific feeling

to be the first person to make a mosquito just drop like that!

I'm sure he was quite moved.

But his joy lasted just an instant.

He quickly realized something.

Mosquitoes mostly appear in summer.

You couldn't use a hibachi in that summer heat.

Was there another way?

Ueyama received inspiration from an unexpected source.

During a business trip to Tokyo, he shared a room with a certain man.

This man's family business was Buddhist altar incense sticks.

Many Japanese homes feature Buddhist altars.

Burned there are incense sticks.

Light the stick, and it releases a thin wisp of smoke.

"Eureka!" thought Ueyama.

He wondered if he could add pyrethrum powder to such sticks.

Returning to Wakayama, he added the powder to an incense stick as a prototype.

He lit it up, and...

A mosquito fell to the floor.

He wondered what would happen if he made it like an incense stick,

so he made a prototype using that know-how.

I think he was happy when he saw it work.

This is the first version of the product Ueyama sold.

After two years of development, it was released in 1890.

The world's first mosquito incense was not a coil,

but a straight stick.

After a great deal of trial and error,

the mosquito repelling incense was finally perfected.

At the time, three sticks would be burned to keep mosquitoes away.

But how did we go from sticks to a coil?

Well, there was actually a major issue with the stick form.

The product had been completed,

but these mosquito incense sticks were not widely adopted nationwide.

The problem was how long they burned.

A 20-centimeter stick burned for just 40 minutes before going out.

What about mosquitoes that came at night?

You'd have to wake up every 40 minutes to light new sticks!

And it's not like they had alarm clocks back then.

Who could do such an unwieldy task?

Ueyama tried making the sticks longer to increase their burning time.

However...

This was dangerous.

How to increase the burning time?

Ueyama pondered to himself.

One day, his wife Yuki called from the garden.

"There's a snake!"

Ueyama ran to the rescue.

In front of Yuki was a snake, all coiled up.

Yuki then said, "What about making the sticks coiled, like this snake?"

I'm not sure if she suggested it then and there, after being surprised by the snake.

But after receiving her idea, he made a prototype wooden mold,

which still remains.

He wrote her name on it,

to give her credit for coming up with the idea, I believe.

He wanted to give her credit for the ages.

Ueyama quickly prototyped a coiled version.

It was 60 centimeters, three times longer than the stick version.

But the problem was how to produce them.

Without the proper gap, the flame would jump the coil,

and it wouldn't burn till the end.

Alongside craftsmen, Ueyama tried various methods day after day.

Finally, they placed a stopper in the middle

and coiled two sticks at once.

This let them make two identical coils in one go.

Here's some rare footage of mosquito coils being made from about 70 years ago.

Skilled craftspeople could produce the coils from a long stick of incense

in just a few seconds.

However, just before the coils went on sale, another problem emerged.

The drying process.

When the coiled incense was dried on a board of wood...

it stuck to the board, cracking when peeled off.

Was there another way?

Ueyama racked his brain for an answer.

Again, it was his wife Yuki who had an idea.

"How about using wire mesh?"

Wire mesh, used for grilling fish.

Fish sticks to an iron pan.

But not to wire mesh.

Ueyama quickly grabbed some mesh and lined it with coils.

If they didn't peel off well, the coils could not be sold as a product.

Nervously, Ueyama waited for them to dry.

About five days passed.

Would the coils peel off cleanly?

Cautiously, Ueyama placed his hand on a coil.

It remained in shape, cleanly peeling off the mesh.

The adhesive surface was small, and because it was wire mesh,

there was some wind from below.

I think that helped reduce the moisture.

The mosquito coils were complete.

He must have been so thrilled to be able to sell them.

With that, the world's first mosquito coils were made available in 1902.

Even now, they are still manufactured in double coils,

and wire mesh is still used in the drying process.

And that was how the mosquito coils came to be mass produced.

Since then, the product has been used in many countries and regions around the world.

How do experts view this invention?

We spoke to Kasai Shinji, who researches insects that cause diseases.

Welcome to the show.

Thank you.

Can you tell me specifically what diseases mosquitoes carry?

In terms of mortality rate, it would be malaria.

Mosquitoes also spread dengue fever, chikungunya fever,

Zika virus, yellow fever, and so on.

The animals that cause the most deaths in the world aren't bears or sharks.

They're mosquitoes.

Mosquitoes are vectors for all these diseases,

so they pose a great threat to humans.

What would you say is the value of mosquito coils?

It's been over 130 years since their development.

I don't think there are many people that doubt the effectiveness of mosquito coils.

I often go on research trips to Southeast Asia,

and it's common to see the mosquito coils there.

So many people believe in the product, it's won their trust,

and its effectiveness is not under doubt.

That's quite a large contribution, I think.

What would you say about the relationship between humans and mosquitoes going forward?

There is climate change, which increases the number of places

where disease-carrying mosquitoes can live.

In Japan, we're seeing the range where Asian tiger mosquitoes are distributed

continue to move north.

So it doesn't look like mosquitoes are going anywhere,

and the problems associated with the diseases they carry

are also going to continue to be an issue.

Looking at all that,

I think humanity is still going to be fighting mosquitoes for a long while yet.

Thanks for joining us. Great speaking with you.

Thanks for having me.

"Top Niche Creations."

Our next segment is "Top Niche Creations."

This time, we're looking at these.

Stripped screws.

I'm sure many of us have tried in vain to get one of these out with a screwdriver.

A certain Japanese company looked for a way to deal with these troublesome screws.

We got a behind-the-scenes look at these special tools.

A tool maker in Osaka.

It's a small firm, with just 40 employees,

but a unique tool produced here is known worldwide.

This is our tool.

Just what kind of tool is it?

Developer and CEO Takasaki Mitsuhiro explains.

First, look at this.

A cross-shaped screw.

If you use a screwdriver of the wrong size...

as you can see, it strips the screw, and a screwdriver won't be able to turn it.

In come the pliers developed by Takasaki.

They look like normal pliers at first, but...

Just grab the screw and turn.

Wow! The screw was easily removed.

Look closely, and you can see that the pliers firmly grip the head, allowing it to turn.

The secret is in the uniquely designed tip.

When gripping a screw head, normal pliers make this slanted shape.

But Takasaki's pliers line up in parallel, like this.

Compare them, and the difference is clear.

Plus, the tips have these vertical grooves, so they don't slip when turning.

Normal pliers have horizontal grooves.

With horizontal grooves,

the direction of rotation of the screw is aligned with the groove,

so the pliers slide.

With vertical grooves, there's enough friction to prevent slipping.

That's the purpose of these grooves.

The pliers went on sale in 2002.

In an industry where 10,000 units is considered a hit,

these have sold some 770,000 units.

They've been patented in and outside Japan,

and are now exported to places like China, the U.S., and Europe.

They're beloved worldwide.

But in 2008, after the tool was released,

the firm suddenly found itself in peril.

The financial crisis.

The construction industry, which the firm had relied on for sales, was in dire straits,

throwing the firm into the red for the first time.

To create a new product that would bring things back into the black,

Takasaki turned to feedback received from customers.

He read them all, diving into what his customers found important.

He discovered that many customers wanted to be able to remove truss head screws.

Truss head screws are used in things like furniture and exteriors,

on things where a normal head would be bad.

That makes them hard to grab.

People had a big need to remove these hard-to-grab truss head screws.

Out of that emerged this new product.

At first glance, they look the same as the previous pliers.

With these, you can grab and remove truss head screws.

The secret is the shape of the tip.

The corners of the first version have been removed.

As a result, the tip adheres well to low heads, allowing them to be gripped.

The new pliers were a hit,

selling over 100,000 units a year and helping save the firm.

But thereafter, a new demand started to build.

Dealing with screws whose heads don't pop out at all.

Customers wondered if there was a way to remove such screws.

Screws whose heads don't emerge at all

are called "flathead" or simply "flat screws."

Once you screw them in they're totally flat against the surface.

Here's a flat screw that's been stripped.

When it's like this, of course, the pliers can't grip it.

Not at all.

How to unscrew screws that can't be gripped.

Takasaki pondered the problem for days.

He set his eyes on the furthest points of the stripped portion,

where four small corners remain.

He then developed this tool. Look closely at the tip.

Compared to a normal screwdriver, the cross-shaped tip is thicker.

Try this on a stripped screw head, and...

It grips the remaining four points so it can be unscrewed.

The specially designed tip grips the faint corners, and the screw can be removed.

Takasaki has developed over 30 screw removal tools.

His dream is to solve every screw problem imaginable.

I want to help people facing problems with screws.

It may be a niche, but it's a global niche.

It's a universal need,

so there's a large worldwide market for this.

I definitely want to keep trying new things in this field.

Hold up! There's more.

Like these hex screws.

Sometimes the socket gets totally worn out, right?

The company developed this tool with a drill at the head.

It burrows into the socket, providing a tight grip for removing the screw.

They've come up with a special tool for each type of screw. It's amazing!

That's all for this episode of "Japan's Top Inventions."

We'll leave you with what came next for the mosquito coils

from the first half of the show.

See you next time! And stay inventive.

(The mosquito coils were invented in Japan some 130 years ago.)

(Since then, companies have created other products to repel mosquitoes.)

(This type releases insecticide by heating a pad containing it.)

(This diffuser type works by vaporizing a liquid insecticide.)

(And one spray from this keeps mosquitoes away for 12 hours.)

(These products are helping to prevent the spread of mosquito-borne diseases.)

Mosquito coils were born in Japan, and Japan continues to lead the field.

There's still much work left in the battle with mosquitoes.