Story of the Makers SP Edition: Visiting the people who make the "Life Knife" with Akira Minagawa in Sakai

Single-edged Japanese knives, which are sharp and can cut food without damaging its fibers, have made a great contribution to Japanese food culture. However, there are few opportunities to use them in modern Japanese life. We wanted to reexamine the Japanese knives that have enriched Japanese food and spread their appeal once again. With this in mind, Kamaasa Shoten consulted with Akira Minagawa, a designer at Mina Perhonen who designs a wide range of everyday items such as furniture and tableware, as well as clothing and textiles. Based on the request of Minagawa, who is also known to be a fan of cooking, an original Japanese knife was created in Sakai, Osaka.
The aim was to create a knife that "lives together with the maker and the user." In Sakai, Osaka, one of the leading producers of Japanese knives in Japan, knives are made in a division of labor system, with blacksmithing, sharpening (edge ​​attachment), and handle manufacturing. A single knife is finally completed after a relay of handiwork by highly specialized craftsmen. To learn about the background of knife making and the passion of the craftsmen, we visited the city of Sakai with Akira Minagawa.

Click here for details on the Life Knife

Minä perhonen designer / founder

Akira Minagawa

Founded "minä", the predecessor of "minä perhonen" in 1995. Centering on textile design using mainly hand-drawn patterns, she is engaged in design activities that are close to everyday life, such as clothing, furniture, tableware, and spatial direction for stores and accommodations. She has also provided designs for textile brands such as Denmark's Kvadrat and Sweden's KLIPPAN, and the Italian ceramics brand GINORI 1735, and has worked on illustrations for newspapers and magazines.

TOPICS

• TOPICS 01Production area: Sakai City, Osaka Prefecture
• TOPICS 02Blacksmith : Tanaka Uchihamono Seisakusho
• TOPICS 03 Sharpening: Kawakita Cutlery
• TOPICS 04 Pattern making: Kanakugi woodworking shop
• TOPICS 05 "Life Knife" The meaning behind the name

TOPICS 01Production area: Sakai City, Osaka Prefecture

Sakai City, Osaka Prefecture, is one of the six major production areas of blades in Japan. It is said that the foundation of the development of blacksmithing technology was the gathering of people who made earthen tools for the construction of the ancient tombs that remain in Sakai City to this day. In the 16th century, the sharpness of "tobacco knives" used to chop tobacco leaves became famous, and the Tokugawa Shogunate allowed them to be sold with the "Sakai Kyoku" seal, which led to the flourishing of knife making in Sakai. This tradition was passed down to the making of kitchen knives, and "Sakai forged knives," which are handcrafted one by one by craftsmen through a division of labor, became famous for being used by professional chefs. Most of the Japanese knives sold at Kamaasa Shoten were made in Sakai. This is the background behind why we asked Sakai craftsmen to make original Japanese knives in collaboration with mina perhonen. Minagawa Akira, founder and designer of mina perhonen, and Tanaka Keiko, designer and representative, visited Sakai.

From left: Akira Minagawa and Keiko Tanaka

Since the company was founded in Hachioji, home to traditional local textile and dyeing factories, Minagawa has always been close to manufacturing sites.
Since joining the company in 2002, Tanaka has been creating a wide variety of textiles through close collaboration with people at various factories. Even in a wide variety of collaborations, including furniture and tableware, the two of them visit the factories and workshops of their partners to closely observe the craftsmen at work. This time, of course, they visited all of the knife-making sites.

Their guide was Baba Shuzo of Baba Cutlery Manufacturing, which has supported Sakai's manufacturing scene as a knife wholesaler and blade sharpening workshop for over 100 years since its founding. As they toured each workshop by car, they could see knife-related companies and workshops all over the city, giving them a real sense that Sakai is truly a city of cutlery.

TOPICS 02Blacksmith : Tanaka Uchihamono Seisakusho

From left: Yusuke Okugami, Yoshikazu Tanaka, and Yoshihisa Tanaka

The first place we visited was Tanaka Uchihamono Seisakusho. Here, master Tanaka Yoshikazu, his son Yoshihisa, and apprentice Okugami Yusuke are doing their blacksmithing. According to Baba, "The process of placing steel on a soft iron ingot, heating it to make it one (forge welding), and then hammering and stretching it is called fire-forging (forging), and Sakai is said to be better than other production areas. One of the top craftsmen is Tanaka Yoshikazu. His knives have good steel retention and maintain their sharpness." In front of the furnace in the dimly lit workshop, Yoshikazu was repeatedly hammering the heated ingot and steel, gazing at the blazing fire.

"Mild iron and steel stick together at about 1100℃. Then we hammer it at about 800℃. This is what determines the sharpness," says Yoshikazu. When Minagawa asked, "Can you tell the temperature by looking at it?" he immediately replied, "I can tell from experience. I judge it by the color." If the temperature is not properly controlled, it will become brittle and chip. The steel used in the "Life Knife" is Shirogami No. 2, but the appropriate temperature seems to differ depending on the steel. Minagawa was surprised when Yoshikazu said, "The color of the sparks differs depending on the steel."

To lower the temperature, the steel is left to rest overnight in straw ash. Once the temperature has dropped, it is hammered again, this time heated to around 800℃ using pine charcoal from Iwate, which is suitable for delicate temperature control, and then quenched by immersing it in water to rapidly cool it, hardening the steel. It is then "tempered" (reheated) to make it tougher and less likely to chip. It is hammered again with a hammer, and any distortions or warping caused by the steel shrinking are carefully removed.

The knife is rested in straw ash to lower the temperature. On the back of the blade, an original logo is engraved featuring the Kamaasa Shoten logo above the "choucho" design, one of Mina Perhonen's signature designs.

Before hardening, a mark is stamped on the boundary between the steel and the soft iron. This is called "jiuchi" and if it is done at this stage, the mark will remain black. "If you make it properly, even if an amateur uses it every day, it will last 20 to 30 years," said Yoshikazu. Minagawa was impressed and said, "I didn't know there were so many steps. It's a really honorable job that is backed by experience and intuition." Tanaka also nodded deeply.

TOPICS 03 Sharpening: Kawakita Cutlery

Kawakita Ippei, second generation owner of Kawakita Cutlery

Next we visited Kawakita Hamono. Here, we performed the process of sharpening the blade, known as "honing (hazuke)." "The job of a blade sharpener is to sharpen the hardened knife on a rotating whetstone while pouring water on it to prevent it from burning, and to remove any dents or scratches remaining on the knife to leave it in a beautiful condition," explains Baba. On this day, Kawakita Ippei, the second-generation owner, was working alone. The impressive wall of the workshop is covered with red powder from the whetstone and iron powder from the knife, which have been mixed together like a stalactite cave. Standing in front of this, Kawakita first places the knife on a wooden mold, then roughly sharpens the entire knife on a rotating whetstone while pouring water on it.

After that, it is hammered to remove any distortion and sharpened again. Once the rough sharpening is complete, the final sharpening begins. The blade is sharpened even thinner so that it can actually cut. "It's just a matter of sharpening, fixing, sharpening, fixing. If steel is hammered too much it can crack, so we are very careful when hammering." Minagawa and Tanaka look intently at Kawakita's work.

Kawakita carefully smooths out the depressions (urasuki) on the underside of the blade made by the forge, and further polishes it with a disc-shaped polishing tool called a buff. "This buff is unique to Sakai. It is polished with corundum, a type of abrasive, attached to a polishing cloth with glue. We use two types of buffs when just sharpening the small blade, but four or five types when sharpening the blade properly." Finally, the surface is carefully finished by hand sharpening, buffing, and paper, gradually making the blade finer. "It takes about two days to finish a set of about 20 to 30 blades," says Kawakita. "It's a collaborative effort with the blacksmith," he explains with a smile.

TOPICS 04 Handle making: Kanakugi Woodworks

Shuhei Koura, fourth generation pattern craftsman at Kinkugi Woodworks

Metal Nail Woodworking Shop

Our last visit was to the Kanakugi woodworking shop, where the handles of knives are made. Here, fourth-generation handle craftsman Shuhei Koura creates handles using traditional Sakai methods. In the workshop, there are rows of samples of wood that will be used to make the handles. "We handle a wide range of tree species, but the most commonly used is magnolia. It is a material that was used for the blades of takageta wooden clogs, and is characterized by its water resistance and ease of processing. Yew has also become popular recently. It is not as expensive as ebony, but it is a hard and durable material. The cherry tree that Minagawa chose is similar; it is harder and more durable than yew," says Koura. Minagawa adds, "I was shown various tree species, and I chose cherry tree because I liked its light feel."
There are four main handle shapes: round, shinogi, octagonal, and half-round. This time, after carefully considering how it would feel to hold, Minagawa decided on a "half-round handle" shape.

The handle is made of hard cherry wood that is resistant to corrosion and feels good to the touch, giving it a warm wooden feel. It has fine grain, a dense texture, a glossy finish, and is highly durable. In addition, to prevent fatigue even when used for long periods of time, the upper part is fixed in the hand when gripped, and the semi-round lower part is shaped to fit gently on the fingers. (Image: Kamaasa Shoten)

The process of making the handle starts with shaping the square piece of wood with a disk. Once that's done, a hole is drilled where the knife will go. An iron rod heated to an extremely high temperature with coke is inserted into the hole drilled, and the piece is tempered, a method unique to Sakai. As smoke rises, Minagawa and Tanaka both exclaim in surprise, "Amazing!"

After that, the baked holes are neatly finished, cut to the same length, polished with three types of paper, and then coated with wax and polished to make it beautiful.
"Finishing with wax gives it a gentle feel. Knives are sharp, so I wanted the handle to be gentle," says Oura. "This knife feels natural to hold, and doesn't bother me. I think that means it's easy to use.
"I think this kind of finishing is a big factor," says Minagawa, who seems convinced.

Finally, it is Baba's job to insert the knife into the handle made by Oura (attaching the handle) and bring the knife into a form that is ready for shipment.
Once we have checked everything and confirmed that it is in good working order, we box it up and send it off.

TOPICS 05 "Life Knife" The meaning behind the name

"The name 'Life Knife' expresses my desire for the person who uses it to feel like 'I'm going to take good care of it and use it for a long time.' I didn't just choose it because it had a nice visual design, but I wanted people to feel that this is an important item that will be used with care. After seeing the makers at work this time, this feeling has deepened even further," says Minagawa.

There was another unique perspective that Minagawa had behind the naming.
"When you sharpen a knife, it gradually becomes smaller, but at the same time, the evidence that it has been used for a long time disappears. I thought that was interesting, and somewhat philosophical. To put it succinctly in words, it became the 'Knife of Life.' I would be happy if the person who uses it could see it as 'a tool for living.'"

Minagawa owns quite a few knives, but has never owned a "life knife" that he considers his own. He says, "I'm looking forward to seeing how this knife will become familiar to me."
Ms. Tanaka, who has been watching Minagawa make the knives closely, said happily, "It's not often that we come across a knife that we like. But with this knife, the excitement I feel when cooking will stay with me for a long time."

Use it every day, sharpen it when it becomes dull, and use it again. May the maker's thoughts be connected to the user's life. And as a tool to support daily meals for decades to come. May the "Life Knife" be that kind of existence.

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Written and edited by: Shiyo Yamashita Photography by: Masaaki Inoue (TOPICS 1-4) Hiroki Hashimoto (TOPICS 5)