I wanted to turn his generosity into something tangible—and not let his kindness go to waste.

He had introduced me to two tools: a Surform and a Japanese saw rasp known as a nokoyasuri. I searched for them at home-improvement stores and online, and once I had both in my hands, I was ready to put them to the test.

But first, I had to rebuild the core from the very beginning.

The first time I made one, everything had been unfamiliar. I had spent a great deal of time experimenting, making mistakes, and trying different methods.

This time, however, something curious began to happen.

The work was gradually becoming second nature to me.

“This part will be more accurate if I do it this way.”

“That task will go faster if I try a different method.”

Little by little, I was beginning to make these judgments and improvements as I worked.

Once again, I prepared a core by filling each opening in the cardboard grid with Styrofoam.

I decided to begin with the Surform.

“Little by little. Take it slowly.”

I repeated those words to myself as I carefully began shaping the surface.

The tool and the material seemed to be well matched. Unlike the ordinary file I had used before, the Surform removed the Styrofoam steadily and efficiently.

“I’ll keep shaping the whole board this way.”

Before long, I was completely absorbed in the work.

I had started in the morning, but when I finally looked up, it was already past noon.

And I had only finished shaping one side of the rail.

When I stopped for a moment, I realized just how tired my right arm had become. If I kept going with only one arm, I might not have enough strength to finish the job.

So I made a simple decision.

After lunch, I would switch hands.

I quickly finished my meal and headed straight back to the workshop.

“All right. Now I’ll try the other tool—the nokoyasuri.”

Maybe changing tools would make the work faster—and give my arm a little relief.

I began shaping the Styrofoam with the nokoyasuri.

With hardly any force at all, it removed the material rapidly.

The difference was remarkable.

“This is it. This is the right stuff!”

At last, I had found the right tool for shaping this particular core.

I continued by forming the curved outer edges of the board, then gradually shaped a slight rocker into the nose and tail.

It took about three days to reach this stage.

But somehow, there it was.

Something that finally looked like a surfboard.

I held the prototype in my hands and examined it carefully from every angle, thinking about what I should do next.

There was satisfaction in finally seeing its shape.

But there were also problems.

Four of them.

The first was the rocker. Shaping it into the nose and tail required far too much time and effort.

The second was the combination of Styrofoam and cardboard. The Styrofoam itself was easy to shape, but the cardboard framework was not.

Because the two materials had different levels of hardness, they could not be removed at the same rate. Uneven steps appeared on the surface.

Then came the third problem.

Every opening in the framework had been completely filled with Styrofoam.

And that made me stop and wonder:

Had I really reduced the amount of plastic at all compared with an ordinary plastic surfboard?

The fourth problem appeared while I was shaping the curved outer edges. Pieces of Styrofoam glued to the framework kept breaking away.

Each time it happened, I had to stop, glue them back into place, and wait before continuing.

The work was not progressing as smoothly as I had hoped.

“How could I solve all of these problems?”

I had finally managed to create the silhouette of my first surfboard prototype.

Yet, at the very moment its form began to emerge, a whole new series of problems—problems I had not been able to see before—came rushing to the surface.