---Please tell us about the unique features and new aspects of "SHIGA".

Yokoyama (Leader): The biggest feature is that it maintains a minimalist and beautiful design while also providing excellent seating comfort.

Typical office chairs are characterized by their multi-functional design, allowing for fine adjustments to suit each individual sitter. On the other hand, "SHIGA" prioritizes comfort even in environments with high user turnover, such as open spaces and meeting rooms. Therefore, we aimed for a minimalist chair that anyone can sit in naturally, by minimizing individual settings such as the strength of the backrest recline.

One area we focused on most was "making the gearbox thinner." The gearbox is the central unit located beneath the chair's seat, which controls and integrates movable functions such as adjusting the seat height and reclining the backrest.

Kimura (Mechanical Design): In typical office chairs, the more functions there are, such as the ability to adjust the degree of back recline and the forward/backward adjustment of the seat, the thicker the mechanical box tends to become.

For the "SHIGA," in order to achieve a minimalist design, we narrowed down the functions to just two: initial backrest angle lock and height adjustment, and challenged ourselves to make the mechanism thinner. Furthermore, we delved into the internal structure, and by deliberately splitting the spring, which is usually made up of one, into two and arranging them horizontally, we were able to achieve an even thinner gearbox.

Ban (Mechanical Design): One of the new features is that it combines two functions into a single lever. Rotating the lever allows you to raise and lower the height, and pressing the button at the tip locks the angle.

Kimura (Mechanical Design): For the rocking function, we've adopted the "Ankle Move Synchro Rocking" system. This mechanism uses the ankle as a pivot point, allowing the backrest and seat to move in conjunction, which is said to provide a comfortable rocking experience without causing any discomfort to the human body.

In "SHIGA," instead of having a "rebound force adjustment function" that adjusts the strength of the rebound when the backrest tilts, we prioritized a design that provides a comfortable seating experience regardless of body type.

Amiura (Back Design): A distinctive feature of "SHIGA" is the horizontal line on the back, which creates a sense of continuity when the units are lined up in a row. The key points are that the back is actually separate and that the mounting elements are completely invisible from the outside.

A major consideration was whether to assemble separate parts to create the lines, or to simply make it look like there were lines. However, through prototyping, we concluded that actually dividing the parts was better for creating sharp lines.

The chair's backrest is visible from both the front and back, so it can't simply be attached with screws from the outside. Furthermore, its quality greatly impacts the product's value. The challenge was how to glue the divided parts together without showing the attachment points while ensuring strength. This required a lot of trial and error.

Amiura (Back Design): While it's important that the sewing lines and back panel division lines are straight and neat, this is a mass-produced item, not a one-of-a-kind piece, so we focused on the component configuration to ensure a consistent finish no matter who is doing the work.

While chairs with lines on the back exist, I think chairs with a backrest that is actually divided into sections are very rare.

Nozawa (Seat Design): The seat surface looks flat from the outside, but the core material inside is shaped like a bowl that firmly cradles your bottom.

​To ensure comfort while sitting, we've incorporated an internal design that isn't visible from the outside, preventing pressure on the back of the thighs and impairing blood circulation.

It's clear that everyone went through a lot of trial and error in designing this chair, prioritizing aesthetics while maintaining its functionality.

---I hear that various ingenious designs have been incorporated into the legs and elbows as well.

Yamaoka (Leg Design): There are two types of legs: aluminum legs and pipe legs, and each has its own unique features. With the aluminum legs, we focused on achieving both lightness and strength. Because the legs are horizontal to the ground, the way forces are applied tends to be unfavorable, and since the legs themselves are long and slender, we felt it was difficult to maintain overall strength.

Therefore, we adjusted the thickness of the inner wall of the legs in 0.1mm increments without compromising the exterior design, achieving a balance between lightness and the maximum strength that the aluminum would not break. Furthermore, we actually ensured strength by setting the angle of the top surface of the legs to 92.4 degrees and the bottom surface to 90 degrees.

Yamaoka (Leg Design): Next, with the pipe legs, the challenge was how to bundle the five sections together. Here too, we focused on the positional relationships and shapes of the parts to increase strength without affecting the appearance. We had many discussions with our manufacturing partner about how to assemble them to realize our concept.

Okumura (Elbow Design): In designing the elbow, I focused on achieving a "smooth texture" when it moves. I tried various methods, but by using gears, which are not usually used, I was able to create a design that doesn't make a rattling sound when locked.

Furthermore, to match the aluminum material of the chair frame, we also challenged ourselves to make the covers for the movable armrests, which are usually made of resin, out of aluminum. This ensures that the overall design and texture are not compromised even with the covers attached. There are many constraints on the shapes that can be made with aluminum, so we had to be very creative to create them.

---It's in the parts that aren't visible from the outside that the meticulous attention to detail is truly evident.

---Product designer Fumie Shibata, who was in charge of the design for "SHIGA," has been praising ITOKI's manufacturing capabilities. What do you think are the reasons for their high level of technical skill?

Yokoyama (Leader): I think the reason is the "people." In manufacturing, you interact with people from various departments, but no one easily says "it can't be done." Everyone is genuinely thinking about how to make it happen. Perhaps because of the background of creating numerous new products so far, I feel that we have gathered reliable senior colleagues who have an even stronger passion than we do.

Ban (Mechanical Design): Nobody compromises. Especially when it comes to quality and safety, we conduct tests so many times that you might think, "Do we really need to go that far?"

Yamaoka (Leg Design): Of course, they have a high standard for quality, but I think their strength lies in their ability to think about and implement ways to further improve usability and appearance, rather than being satisfied once safety is ensured.

Kimura (Mechanical Design): It's great that the design and manufacturing departments are in the same space. I don't feel any power imbalance, either physically or psychologically, so I feel a sense of determination to create something great from a level playing field.

---So it's not just about having the technical skills, but also about having a strong, uncompromising mindset that leads to high-quality manufacturing.

---As a creator, are there any aspects of "SHIGA" that you would like people to pay attention to?

Amiura (Back Design): What I find most impressive is that the mounting points, such as screws, are completely invisible. I think it's amazing that we were able to completely hide elements that would otherwise be considered design clutter.

Nozawa (Seat Design): I'm proud of the sharp edges on both the back and seat, even though it's a sewn product. It's a material that tends to become rounded, but I like how it gives a crisp impression.

Okumura (Elbow Design): I love the texture of the aluminum. I especially like the part where the elbow parts go under the seat and the area around the lever!

Yamaoka (leg design): For me, it's the beauty of the coloring. I went through many color mixing cycles to get the target color.

Ban (Mechanical Design): We are proud not only of the design, but also of the safety features that are unique to Itoki. For example, we have installed a wall in an unseen area to prevent fingers from getting caught in the gap when the seat and backrest move. As a designer, I am proud that we have pursued comfort and design while also ensuring safety.

---I can sense the dedication and affection each person has for their assigned area.

"SHIGA" was created with the unconventional, flexible thinking and enthusiasm characteristic of a young team. While stripping away unnecessary functions, it pursues comfort, and the meticulous technology that permeates even the unseen parts is filled with ITOKI's pride in manufacturing. In the second part, we ask the members in detail how they tackled the difficult challenge of "designing every part from scratch" and how they grew as a result. Please be sure to check it out as well.

The second part of the article will be published soon! Please look forward to it.

Experience "SHIGA" at the showroom.​