installation and technical support, and advice.
We are experts in wood flooring materials. Contrary to general contractors,
designers and architects, we truly understand the factors and requirements
unique to the kendo-jo flooring. After all, we are also ardent practitionersof the art of kendo ourselves.
As experts in the unique requirements of kendo-jo flooring, we provide flooring
solutions which are safe and make“keiko”, the eWxercises and training,easier to do. We use 100% domestic Japanese species, uncoated,to create floors with the right amount of structural elasticity or“give”.
Unlike urethane coated flooring found in gymnasiums, we provide kendo-jo
flooring which has a kind of warmth and a proper amount of cushion,
creating a high level of safety.

Gokan Ltd.

剣道場 床建築工房

http://architecture-dojo.com/

We provide seamless, complete service from supply of flooring materials,

One kendo-shi ’s reflections on the kendo-jo
I began practicing kendo while in primary school.
Even today while running a specialty wood flooring
company in Shinkiba, Tokyo, I continue to practicekendo.
I used to believe that torn Achilles tendons, heel
injuries, calluses and other foot injuries were anatural part of practicing kendo.
Then, a few years ago, I had the opportunity top e r f o r m“ k e i k o ”a t a“ r e a l ”d o j o . T h e b u r d e nplaced on my feet was quite different than any
other dojo flooring that I had experienced before.
This was the first time I had experienced what areal kendo-jo floor was supposed to feel like.
where other martial arts are practiced.
The floor felt cushioned, gentle and warm to thefeel. Even when stepping heavily as is done during

In other words, gymnasiums are designed primarilyk e n d o“ k e i k o ” , I f e l t l i t t l e o f t h e s h o c k o r

for sports where the athletes wear shoes, whereas

burden of the step in my feet. With this type ofin kendo where the kendo-shi are barefoot. Thefloor, older people with weaker feet and hips andnon-slip surfacing on the gymnasium floor

those with big blanks in their practice can practicesurfaces has a damaging effect on the“keiko”safely with less risk of injury.

kendo-shi’s feet.

As a professional in the wooden flooring industry,

The floor of a gymnasium is too hard for the feetI could not help but wonder why the same actionsof the kendo-shi when the feet thump down uponon two different wooden floors felt so differently.

the floor and often causes pain the heel. During
the ten years plus that I and other ken-shi haveI decided to travel around Japan to the older,been practicing kendo mostly in gymnasiums, I

traditional kendo-jo and research the reasons whyrealize that this is the reason for so many of thethe floors were so much better. What I realized isinjuries.

that the ideal floors were in kendo-jo dedicatedsolely to kendo, and not a general purpose dojo

http:/ / a rch itectur e-d o j o . co m/

So why has this problem arisen?

1

F i r s t o f a l l , i n t h e c o n s t r u c t i o n p l a n n in g s t a g e ,In the end, inevitably, the specs become the same, aplanners had insufficient knowledge of kendo floors.

urethane coated gymnasium floor.

Essentially, a gymnasium floor was constructed, but

I don’t think that is acceptable.

t h e n a m e“ k e n d o - j o ”w a s s l a p p e d o n t o t h e
structure.

So, what kind of kendo-jo is really made for thekendo-shi?

However, even someone like myself who does kendo
did not notice the problem, so it is probably too

I know how easy it is for someone who has only amuch to ask that architects who do not practicelittle experience with kendo to perform“keiko”onkendo to have specialized knowledge.

a real, solid wood floor built specially for kendo.

Another problem, is the mentality of the contractors

There is little demand for new kendo-jo’s, and very

and others involved. Often, the modus operandi isfew people involved in their construction have ever“just get it sold and out the door”with insufficientgotten their hands on the“Kenshi News”publication

thought into what is the right solution.

to help them. The knowledge for constructing aproper kendo-jo has just never been disseminated.

Even if the architects, suppliers and others wantedt o b u i l d a k e n d o - j o in a n id e a l m a n n e r f o r t h eHowever, although there is little demand for new

kendo-shi, there are too few experts or available

kendo facilities, it is quite strange that there has

information to make it possible.

been so little research into the safety of the ken-shi.
As a flooring specialist and a practicing ken-shi, I
wish to promote greater safety in the kendo-jo. I
also wish to promote the greater utilization ofnative wood.
Based on my own“keiko”, experience andresearch, I would like to introduce to others aroundthe world real kendo-jo flooring made for real
ken-shi. And as an expert wooden flooring, I am
committed to furthering my knowledge in this field.
Based on my own“keiko”, experience andresearch, I would like to introduce to others aroundthe world real kendo-jo flooring made for real
ken-shi. And as an expert wooden flooring, I am
committed to furthering my knowledge in this field.

Gokan Ltd.

http:/ / a rch itectur e-d o j o . co m/Mr. Hideki Maeda2

The ideal kendo-jo floor is...
・comfortable and feels good when practicing keikoboard end to end of very old sugi of at least one

・places a minimal burden on the feet of the student“sun”in thickness. The material may be expensive,・has a long usable life span

but it will last a very long time.”*Note:“sun”,pronounced“soon”is a traditional Japanese unit ofWith these three points in mind, plywood type

length measuring 30.3mm (0.8382”).

flooring which does not reduce the impact upon
one’s feet will not be considered. Therefore, weThe material should be mostly of the reddish

will only consider natural wood flooringheartwood. With larger portions of mixed whitesapwood, unevenness tends to develop between theJust having natural wooden flooring does not ensure

two. Similarly, if there are many knots present,that it is suitable for a kendo-jo. In selecting a

unevenness will develop around the knots. Knots will

wood species most suitable for kendo-jo flooring,

also chip, split, partially or fully come out; requiring

we can only recommend one kind.

various procedures to fix the problem and result in
unexpected repair costs.

One of the first characteristics to look at is the“slide”. The ease or difficulty of sliding one’s

From all of the above, the choice material is sugi,feet across the floor in all directions needs to bewhich Japan has in abundance. Sugi has few knots

just right. The feet cannot slide too easily nor too

and its heartwood is red. We use natural Japanesedifficult to slide one’s feet across the floor.

sugi for our kendo-jo flooring.

I n o r der fo r t h e kend o -j o fl oo r t o po sses s t h e

We handle a variety of wood. We can also offer

appropriate sliding levels, the wood surface needs

hinoki, pine and other species. For customers whoto have a certain amount of softness to it.

desire a species other than sugi, we can help you.
Please let us know your needs.

In Japan, decisions on kendo-jo flooring usually boil
down to either hinoki (Japanese cypress) or sugi
(Japanese cedar). However, when considering
surface hardness, hinoki is harder than sugi and istherefore less desirable in this aspect.
Kendo master Hiromichi Nakayama similarly stated,“Hinoki is a very good material, but in winter, it
becomes too slippery and breaks one’s form. To
the degree possible, the material should be a solid

http:/ / a rchitectu r e-d o j o . co m/

3

What is a genuine kendo-jo “elastic”
floor structure?
Overall, what is important for a genuine kendo-jo
floor?
Material thickness, length, width, coatings, durability,construction method and various other factors. If
any of these factors are missing or not satisfied,you just cannot make the ideal kendo-jo floor.
The number one thing to keep in mind is the safetyof the kendo-shi (practitioners of kendo)
Making a safe kendo-jo floor sounds like an easy
thing to do, but unlike judo, almost no research has
been conducted regarding what makes a kendo-jo
floor safe for the kendo-shi.
In order to make a safe kendo-jo, we need to lookat the following issues:type of wood , size of thewood , cushion , construction method , installation
When these are effectively and wisely combined, wehave kendo-jo which . . .
However, to actually realize this, one must have an
・is safe

extensive knowledge of wood, extensive knowledge

・has a long usable life spanin construction and construction methodology, as・reduced costs

well as experience in kendo itself.
Having all three of these bases covered makes meo n e o f a k in d in Ja pa n . A s su ch , I a m u n i q ue l ypositioned to assist with kendo-jo flooring needs.
We will continue to make efforts to promote bothwood and kendo.
When a new kendo-jo floor is to be built, pleasecontact us. We will be glad to help.

http:/ / a rch itectur e-d o j o . co m/4

What is ideal coating?
We recommend no coating at all. For the following

growth rings which creates ups and downs on thetwo reasons, we recommend the kendo-jo flooring

surface. Because of this, an oilwax finish is notremain unfinished.

needed.

When coated with urethane, the flooring loses theAn oilwax finish allows for the long term protection

appropriate amount of“slide”. This places an extraof the beautiful colors, but it also makes the surface

burden upon the feet.

harder and may affect both the“slide”of the floor
and also affect the“give”or elasticity.

We use only natural sugi which has been dried overa long period of time.

An uncoated flooring allows for the proper amount

Unlike laminated wood products, our materialof elasticity,“slide”and warmth of the floor, so we

retains its“elasticity”, maintains an appropriately

recommend that floors remain uncoatedhard surface and is less prone to wear between the

http:/ / a rch itectur e-d o j o . co m/5Customer comments and stories
in the media
The March 19, 2011 edition of the Japan Forest“Compared to the usual urethane finished flooring,

Products Journal newspaper ran a story about one

there is less heat from friction between the bottomof our kendo-jo flooring which used 100% nativeof the foot and the floor. There is less strain on

Japanese woods.

one’s feet when the moving foot comes to a stop.
S in ce w e pr a ctice b a r e f oot, th e te m pe r a tu r e i s

In the story, Mr. Kitada, the most senior manager

another issue we notice. This flooring has more

for the kendo-jo, stated:

warmth than a urethane coated floor.”

http :/ / a rch itectur e-d o j o . co m/6

剣道場 床建築工房
h t t p : // a r c h i t e c t u r e - d o j o . c o m /Gokan Ltd.
Kinokuni Bldg. 4F, Shinkiba 1-6-13, Koto-ku, Tokyo

Tel : 03-3522-4169
Office is closed on Wednesdays
Fax : 03-3522-4170
E-mail : inf o@kendoujou.com