To put my idea of building a surfboard frame from cardboard into practice, I first needed cardboard itself. Rather than buying new material, I decided to reuse the packaging that came home with my shopping.

Using a utility knife and

Before long, I found myself completely absorbed in the process. Simply discovering how the pieces could fit together became unexpectedly enjoyable.

Then, a question came to mind.

How many different ways were there to connect these pieces?

Which arrangement would produce the greatest strength? And was there a structure that could provide flexibility without sacrificing that strength?

One question naturally led to another.

Among the patterns I experimented with, a honeycomb arrangement—similar to the structure found in a beehive—proved to be remarkably strong.

As I looked at it for a while, I began to feel that I had seen something similar before. I could not immediately remember where, but eventually a memory returned to me.

While walking my dog through a small woodland, I had once seen a farmer collecting fallen leaves with a traditional bamboo basket carried on his back. The woven pattern of that basket looked surprisingly similar to the structure in front of me.

It, too, had been created by arranging strips of bamboo in a regular pattern.

The moment I realized this, I felt a sudden surge of excitement.

Until then, I had assumed that honeycomb structures belonged to the world of modern advanced technology—something developed for aircraft and other highly engineered applications.

Yet a similar structural principle had already existed for centuries, quietly cultivated through the everyday lives of ordinary people.

“So this was not something that had only recently been invented.”

Suddenly, what had seemed like separate points connected into a single line. I can still clearly remember the excitement that rose from deep inside me.

That realization led me to another question.

Could it be that traditional bamboo baskets and bags were woven differently depending on whether strength or flexibility was required?

I decided to learn more about the history of bamboo craftsmanship and its various weaving techniques.

As I continued my research, I discovered that in many countries and regions where bamboo grows naturally, people had been weaving it into tools for everyday life for thousands of years.

Baskets, containers, and carrying tools were made using different techniques, each chosen according to its purpose. People understood the characteristics of the material and adapted their methods to provide the qualities they needed.

Thousands of years ago, people were already searching for better ways to live, applying their ingenuity and continually refining their skills. The thought that this accumulated knowledge had been passed down through generations and preserved as culture left a deep impression on me.

Making something is not simply an act of producing a useful object.

It involves observing a material, experimenting with it, finding better ways to use it, and passing that knowledge on to the next generation. Perhaps this continuous process is itself one of the ways human culture is formed.

Returning to the surfboard, I realized that its frame would also need to meet two seemingly opposing requirements.

A surfboard must be rigid enough to withstand the force of waves. At the same time, it also needs a certain degree of flexibility.

While riding a wave, the board can bounce in response to the constantly changing surface of the water. With an appropriate degree of flexibility, it can absorb some of those forces and provide the rider with greater stability.

Strength alone would not be enough.

The structure also needed to move with a certain degree of suppleness when necessary.

After considering how these two qualities might coexist, I arrived at an arrangement similar to the traditional Japanese bamboo-weaving pattern known as Yotsume-ami.

Its lattice structure provides strength while still leaving a subtle degree of freedom for movement.

Rigidity and flexibility.

Although they may appear to be opposing qualities, I began to think that they could coexist within a single structure.

This was how I finally decided on the arrangement of the cardboard pieces that would form the surfboard’s frame.

It was also the moment when cardboard—a familiar modern material—and the wisdom of bamboo weaving, cultivated through everyday life over countless generations, quietly came together in my mind.

But deciding on the structure was only the beginning.

The next challenge was to discover how this flat lattice could be transformed into the smooth, flowing curves of a surfboard.