I adapted the traditional Japanese bamboo weaving technique called Yotsume-ami to assemble cardboard parts into a rectangular lattice core, roughly the size of both hands put together.

My next idea was to cut this lattice into the shape of a surfboard.

It didn't work.

After thinking about it for quite a while, I wondered if filling the empty spaces in the lattice would make it stable enough to cut more easily.

But what should I fill it with?

Since it was going to become a surfboard, the material had to be lightweight and buoyant. At the same time, I hoped it could eventually decompose and return to the earth as an organic material.

My first idea was wood.

I experimented with cutting small wooden blocks to fit inside each 3-centimeter square of the lattice. Although each piece felt light by itself, the total weight became surprisingly heavy. Beautiful wooden surfboards are heavy for exactly this reason.

Then I thought about cork.

It should be lighter than wood and float well, so I visited a home improvement store to look for it. After handling several samples, however, I realized that cork was heavier than I had expected and also quite expensive.

"This won't work for my surfboard."

So I kept walking through the store, searching for another possibility.

"What about pumice?"

Even though it is stone, it floats on water.

I picked one up, but again I concluded that it would be difficult to shape, and the overall weight would still be too much.

Then another thought appeared.

"If shaping solid materials is difficult, perhaps I could make something similar to expanding foam and pour it into the lattice."

After giving it some thought, I mixed starch with water, added a large amount of sawdust, and poured the mixture into the lattice, hoping it would harden after drying.

The next day I visited a lumberyard, collected some sawdust, and immediately put the idea into practice.

It didn't dry after one day, so I left it for several more days.

Finally, when I picked it up and was about to cut it with a saw, I was overcome with disappointment.

Because I had used starch and water, and because it was already early summer, the entire piece had become covered with mold.

"This won't do."

I had placed real hope in this idea, so it felt as if I had suddenly wandered into a maze with no visible exit.

"What should I do now?"

As I sat there sighing, another idea quietly emerged.

"Wait a minute... I need something that can be shaped freely and packed into any space. Something like the clay I used to play with as a child."

But ordinary clay would be too heavy, and it certainly wouldn't float.

"Perhaps there are other kinds of clay."

I hurried to a stationery store.

There I found a clay-like material that wasn't entirely organic, but became remarkably light after drying and was surprisingly inexpensive.

"Yes... this is it."

My confidence returned.

For the first time in days, I found myself looking forward to tomorrow.