Why I Ran 100 Kilometers in Ippon-ba Geta – and Why I Created ippon blade®︎
A traditional Japanese one-tooth wooden sandal led me from barefoot running to a new way of understanding balance, gravity, and movement.
The first thing to understand is the name.
Ippon-ba geta are traditional Japanese one-tooth wooden sandals. Unlike ordinary geta, each foot is supported by a single transverse tooth beneath a wooden platform.
To many people, running a marathon in them sounds like a stunt. It was never a stunt for me.
I ran 100 kilometers in ippon-ba geta because I wanted to know how far the human body could move without fighting itself – and because running had once been the very thing that made me lose touch with myself.
When running became a judgment
I loved moving as a child. Then a race at kindergarten changed something in me.
The children were ranked. I felt as if the result measured more than speed; it seemed to measure our value. From that point, running became entangled with how other people saw me.
I disliked being compared, yet I still wanted recognition. For years, I tried to become the person I thought others would accept. The further I went in that direction, the less clearly I could feel what I genuinely wanted.
Eventually, my health broke down. Illness and injuries accumulated. There was a period when standing and walking became difficult. I lost my work and my home. The identity I had built could no longer hold.
Barefoot on Iriomote Island
I left Tokyo and went to Iriomote Island in Okinawa, in southern Japan. I worked as a nature guide and marine sports instructor. My days became shaped by weather, water, forests, and tides.
I took off my shoes and watch and began running barefoot through the forest.
There were stones, roots, new shoots, insects, wet ground, and places where I could not know exactly what the next step would bring. I had to feel where I was placing my foot. Protecting myself and avoiding harm to the small lives around me were part of the same movement.
If I pushed against the ground too hard, I felt that force return through my sole. If I tensed in advance, my movement became rigid. But when I sensed the surface, received my weight, and allowed the next step to emerge, I did not have to drive myself forward by force.
My body was active, but my mind became quiet.
Barefoot running was not simply exercise. It was a way of returning to direct experience: What am I feeling now? Where am I holding unnecessary tension? Where can I place the next foot without forcing the body or the land beneath it?
That was how running began to belong to me again.
Meeting ippon-ba geta
After returning to Tokyo in 2013, I worked as a personal trainer and continued exploring barefoot and animal movement. Then I encountered ippon-ba geta.
At first sight, their form seemed to express something I had discovered barefoot. A single line of support asked the body to organize itself around an axis. Front and back, left and right, the sensations inside the body and the terrain outside it – all had to remain in relationship.
The first time I wore them, the reaction was immediate. I felt as though I already knew them.
I began wearing them in the mountains. I walked, ran, and kept testing what happened when I stopped trying to control every movement. When excess tension released and my weight came into relationship with the support beneath my feet, the next step could become surprisingly light.
But I also saw a problem. The existing pairs I wore did not always work with the structure and movement of my body. I could sense the possibilities of the single-tooth form, but I could also feel where its shape forced my body to compensate.
Why 100 kilometers?
I did not begin with 100 kilometers. I first ran shorter distances, then half marathons and full marathons. Long distance became a way to test an idea honestly.
Over a few minutes, force can hide mistakes. Over 100 kilometers, the body exposes them.
In April 2017, I completed the Okuizumo 100 km race in commercially available ippon-ba geta. It became the world’s first 100 km race finish in single-tooth geta.
Three months later, I entered the Nikko 100 km Ultramarathon. During that race I experienced a powerful sense of unity between movement, sound, scenery, and time. But on the descents, pain in my ankles grew. I eventually withdrew.
That failure mattered as much as the finish.
It showed me that teaching movement was not enough. If the form beneath the foot worked against the body, the wearer would be forced to adapt to it. I wanted the footwear itself to work more closely with human structure, weight transfer, and movement.
That decision became the beginning of ippon blade®︎.
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Turning sensation into form
I began developing a new form with Mokuen, a Japanese woodworker who was also a mountain walker and barefoot runner.
Our development process started with conversation and continued through the body. I explained what I felt while standing, walking, climbing, descending, and running. Mokuen made prototypes. I wore them, moved in them, and reported what changed. Then we adjusted the outline of the platform, the height and position of the tooth, the path of the straps, and the relationship between them.
Small differences in shape created large differences in movement.
Could the foot settle without being fixed? Could the body receive its weight and move into the next step without unnecessary strain? Could one form preserve the character of Japanese geta while opening new possibilities for contemporary movement?
The golden ratio became part of the design of the first model, 369 MIROKU. Mokuen’s knowledge of wood – planing the platform, fitting the tooth, preserving strength, and finishing each pair – made it possible to turn sensations into a form another person could wear.
ippon blade®︎ 369 was completed in 2018 and introduced publicly in Tokyo on November 11 of that year.
The name ippon refers to a single tooth, a single axis, and a central line through the body. Blade carries the image of cutting away unnecessary tension and attachment, sharpening the sense of that axis.
The point was never imbalance
People often assume that ippon-ba geta are mainly about balancing on something unstable.
For me, that is too shallow.
The purpose is not to freeze the body in perfect balance. A living body is always adjusting. Pressure shifts beneath the feet. The head, rib cage, pelvis, and legs respond to one another. Vision, vestibular sensation, and proprioception continually contribute to posture and movement.
A single tooth makes those changes difficult to ignore.
When someone tries to control everything by force, the movement often becomes stiff. When the necessary muscular work remains but excess bracing is released, the body has room to sense, adjust, and move.
This is why I describe the practice as returning to your axis.
The axis is not a rigid pole. It is a changing relationship between gravity, the body, and the support beneath the foot. You do not possess it once and for all. You keep finding it through movement.
From proving something to sharing an experience
At first, I ran long distances to embody what I believed was possible. Over time, something changed.
The joy was no longer only in what I could do. It was also in watching another person notice a new sensation, move with less strain, or discover that their body had more choices than they expected.
In September 2018, before the first ippon blade®︎ model was released, I completed the Hakusan-Shirakawago 100 km Ultramarathon in commercially available ippon-ba geta. In December 2022, I completed the Tobishima Kaido 100 km Ultramarathon in ippon blade®︎.
Those finishes are part of the story, but they are not its destination.
You do not need to run 100 kilometers. You do not even need to run. Standing, walking, climbing, descending, and breathing can all reveal how you relate to gravity and the ground.
Distance and speed are choices. Awareness begins with a single step.
The question beneath every step
I once ran because I wanted the result to prove my value. Barefoot running taught me to feel again. Ippon-ba geta gave that discovery a visible form. Developing ippon blade®︎ turned it into a practice I could share.
The essential question is no longer, “How can I force myself farther?”
It is:
What becomes possible when I stop fighting my own body and begin listening to it?
That question continues to guide every pair we make, every lesson we teach, and every kilometer I run.
For the complete story, design principles, body mechanics, model guidance, and movement philosophy, read ippon blade: Body Mechanics and Movement Philosophy – The Official Guide on Amazon Kindle.
https://www.amazon.com/dp/B0HKBPRF8W
Learn more about ippon blade®︎ through our official international links:
