Seiko House Hall in Wako, Ginza, is hosting a solo exhibition showcasing the works of Toshihiro Shimazaki, a man of Edo joinery, from his youth to the present. The exhibition is titled "The Work of Woodworker Toshihiro Shimazaki: Reviving Mikurajima Mulberry." A full member of the Japan Crafts Council, Shimazaki's signature pieces include small boxes and inkstone cases made from the finest mulberry wood, Mikurajima Mulberry, as well as accessories like hand mirrors and walking sticks. The exhibition showcases an exquisite fusion of traditional techniques passed down through the generations and the exceptional skills that Shimazaki has developed independently. It truly embodies the very essence of Edo joinery.

The amber color shines and the wood grain stands out beautifully.

There are works of various shapes on display. Each piece shines amber in the light of the pin-spot light, and the beautifully highlighted wood grain speaks volumes. The intricate patterns drawn by the wood grain are the very expression of the long years the tree has accumulated. Even as he touched the wood grain that adorns the piece he himself created, the words that came out of his mouth were unexpected.

"When you purchase a whole log of precious wood, where and how should you cut it to see what kind of grain will appear? In fact, in most cases, you won't know until you actually cut it. This process, called 'Tsuratsuke' (appending), is always a thrilling experience."

So says woodworker Shimazaki Toshihiro, who was born into a family of Edo joiners. Even Shimazaki, who has been involved in Edo joinery for over 60 years, says he was unable to fully grasp the grain of the wood from the raw log. "There were times when I cut it and realized it wasn't really lotus wood, which was a big mistake."

After the "surface" process is applied, the fine wood is left to rest for 10 to 20 years before it can be used for joinery.

"We call the wood planks 'banmono,' but how do you use them after they've been laid down and what kind of piece do you make of them? Which part of the piece will you use the infinite variety of wood grains in? This process, called 'kidori,' determines the quality of Edo joinery."

Joinery is a traditional technique that has been passed down since the Edo period

Let's take a moment to talk about Edo joinery. "Sashimono" is a traditional Japanese woodworking technique that uses no nails or other metal fittings, instead joining materials together with uneven joints called "tenons," and refers to the boxes and other objects that are created using this unique method. It is said that the work of carpenters, who worked on fixtures and furniture, gradually became more specialized.

While Kyo-sashimono, which developed in Kyoto, is elegant with decorations such as maki-e and raden, Edo-sashimono does not use decorations and instead values ​​the delicate beauty of the wood grain and the durability of the lacquer finish. The term "Edo-sashimono" was coined in the mid-40s to compete with the previously existing term "Kyoto-sashimono," so it is not that old, but the techniques of joinery themselves have been passed down continuously since the mid-Edo period.

The unique beautiful grain of "Mikurajima mulberry" and the tenacious wood that supports the tenons

Of the various types of wood used in Edo joinery, Shimazaki treasures a special type of mulberry called "Mikurajima mulberry." As the name suggests, it is the name of mulberry grown on Mikurajima, one of the islands that make up the Izu archipelago, and its neighboring island, Miyakejima.

"It has a unique, beautiful grain that you won't find in mulberry wood from any other region. The grain changes over time. When the log is cut, it is yellowish, but it gradually turns red, and after 100 years it has taken on a more reddish, tasteful hue. Another characteristic of this wood is its strong tenacity. It is precisely because of this strength that it will not break or chip even if you cut small tenons."

"Tenon joints" are used to join pieces of wood together without using nails. Pillars and beams in traditional Japanese houses are also joined with tenon joints, but in this case the tenons are quite large. In contrast, Edo joinery involves making extremely small tenons and mortises, which are then fitted together with precision of less than a millimeter.

The shape and angle of the tenon varies depending on where it is used. Using this technique of tenon joints, multiple boards are joined together to form a three-dimensional object. Moreover, the joints never loosen or rattle, resulting in an extremely sturdy three-dimensional object.

The outside is cotton but the inside is silk

"The outside is cotton, but the inside is silk," Shimazaki told us, a phrase that symbolizes Edo joinery.

"It seems that the word originally referred to the haori coat worn by Edoites. The outer surface of the haori is plain and made of cotton, while the lining is flashy and made of silk. In other words, it is the Edoite style of putting effort into the parts that cannot be seen. This word is exactly the same as the spirit of Edo joinery."

"Putting your efforts into the unseen" - the symbol of this is "mortise and tenon joints." Even when boards are joined using intricate "mortise and tenon joints," unfortunately the "mortise" is hidden and never visible on the surface. This is true of all of Shimazaki's works. The edges of the boards fit together perfectly, fitting neatly together as if they had been glued together. Many of them are made of thin boards. The more closely you look at the works, the more you are overcome with a sense of wonder, wondering where the "mortise" and "tenon hole" are made in these thin boards. It is truly the skill that is poured into the unseen parts. This is the essence of Edo joinery.

The unique, softly rounded shape makes it hard to believe it was made from a combination of boards.

There are some works in the exhibition hall that have a slightly unusual feel. Because joinery is a technique used to join boards together, many works are dominated by straight lines. However, this work is dominated by soft curves, and has an overall rounded form that gives it a gentle presence.

"Is this joinery? It must have been carved from a single piece of wood..."

Thinking this, I looked closely and saw a faint, thin line where the masks joined together. It was proof that the masks were connected. Shimazaki smiled, pleased with his result.

"I wanted to overturn the common perception that joinery is a box made up mainly of straight lines. I wanted to be able to express a generous softness along with the wood grain. Joinery that incorporates these curves is called 'kusemono' (bent objects), and requires a fairly high level of skill. My father used to say, 'A first-class joiner is truly a real master once he can make bent objects.' There are fewer joiners who can do this now."

In his youth, he deliberately distanced himself from traditional Edo joinery

Shimazaki, who studied under his father, Masanari, who was also a joiner, worked on Edo joinery in his youth, but he deliberately distanced himself from traditional joinery shapes.

"My father made traditional pieces and entered them in public exhibitions, so I thought there was no need for me to make pieces in the same style. However, now I have a renewed sense that I need to continue making traditional Edo joinery in order to pass it on to the next generation, while also making pieces that other joiners don't make."

I'm grateful to my father for allowing me to freely use his precious tools.

The workshop had the atmosphere of a truly home-based craftsmanship, and Shimazaki used to work side by side with his father.

"What made me happy was that my father allowed me to use his tools freely."

Craftsmen take great care of their tools, which have a major impact on the quality of their work. Being able to use the tools of his father, who was considered a master, was extremely important to Shimazaki in his younger days.

Most of the tools his father used are now gone. Instead, Shimazaki himself has made many tools himself, many of which are planes.

"There are times when we need to make a very thin plane in a very narrow space. In those cases, we use an extremely small plane and make just one small shave. We have over 100 different types of planes on hand so that we can handle any situation."

Only a small portion of the tools he made were on display at the exhibition. After looking at the planes of various shapes and sizes, I faced his work again and felt that each one had become even more brilliant.

◆Art exploration diary ~ Exhibition information

The Work of Edo Sashimono Woodworker Shimazaki Toshihiro - Reviving Mikurajima Mulberry Wood -

Date: September 26, 2025 (Friday) - October 5, 2025 (Sunday)

Time: 11:00 – 19:00 until 17:00 on the last day