This 180 mm mukimono is another highly unusual ultra-thin honyaki knife created by Shiroyama Knife Workshop.

With a spine measuring approximately 1.9 mm, it is significantly thinner than many conventional professional knives, which may measure around 3 mm depending on their design and intended use.

Its compact dimensions and lightweight construction allow the user to guide the blade with minimal physical strain. This is especially valuable during detailed vegetable preparation, where small adjustments in angle and pressure can directly affect the result.

In the video, the knife enters daikon smoothly during katsuramuki. Its low cutting resistance allows the blade to move with a fluid and controlled sensation.

One of the most interesting observations in the demonstration concerns food release.

Highly polished knives can sometimes cause moist ingredients to cling to the blade surface. However, during the demonstration, the daikon separates from the blade more freely than expected, despite the knife’s mirror-polished surface.

This can help reduce interruptions during precise vegetable work and allow the user to maintain a smoother rhythm.

The knife is finished with an ebony handle and saya, giving it a refined and understated appearance that complements its highly specialized performance.

This is not simply a beautiful knife. It is a precision tool designed to support demanding handwork.

As with the ultra-thin yanagiba, it should be handled by users who understand the fragility and limitations of extremely thin, hard blades.

Image captured from a video by Japanese Food Technology Channel on YouTube.

• Knife type: Mukimono
• Blade length: 180 mm
• Construction: Super Steel Honyaki
• Approximate thickness: 1.9 mm
• Finish: Mirror polished on both sides
• Handle: Ebony
• Primary use: Katsuramuki and precision vegetable work
• Recommended user: Experienced and professional users

Extremely thin, remarkably light, and designed for uninterrupted precision work.

Although both knives share an ultra-thin honyaki construction, they were created for different forms of precision.

The 300 mm yanagiba uses its length, low cutting resistance, and controlled flexibility to support long and delicate slicing movements.

The 180 mm mukimono concentrates the same ultra-thin philosophy into a shorter and more agile form, making it suitable for detailed vegetable work and precise blade control.

Yanagiba 300 mm

• Primary purpose: Sashimi and delicate slicing
• Approximate thickness: 1.8 mm
• Mirror finish: One side
• Main characteristic: Long, flexible, and highly responsive
• Notable observation: Razor-like cutting sensation
• Best suited to: Experienced sashimi professionals

Mukimono 180 mm

• Primary purpose: Precision vegetable work
• Approximate thickness: 1.9 mm
• Mirror finish: Both sides
• Main characteristic: Compact, light, and highly controllable
• Notable observation: Smooth cutting and notable food release
• Best suited to: Experienced vegetable-work specialists

They are not competing versions of the same knife. Each one applies extreme thinness to a different culinary technique.

An ultra-thin blade is not automatically better for every task.

Reducing blade thickness can decrease cutting resistance and improve responsiveness. It can allow the knife to enter food smoothly and react more directly to subtle movements of the user’s hand.

However, a thinner blade also contains less material to withstand impact, twisting, and lateral pressure.

These knives should never be used for:

• Bones
• Frozen food
• Hard squash
• Prying or twisting
• Cutting tasks that require excessive force

They should also not be dropped, struck against hard objects, or used with a cutting motion that places sideways pressure on the edge.

The value of these knives lies in specialization, not versatility.

In the right hands and for the right work, their extreme geometry can offer a cutting experience that a more conventional blade cannot reproduce.

The term “honyaki” refers to a demanding method of knife construction in which the blade body is formed from a single primary steel, rather than the laminated combination of hard steel and softer iron commonly used in many traditional Japanese knives.

Producing a honyaki blade requires advanced control during heat treatment. The risk of warping, cracking, or failure is greater, and each stage demands considerable skill and experience.

The Super Steel used in these knives is a proprietary semi-stainless steel developed by Shiroyama Knife Workshop. Its exact composition and detailed steel designation are not publicly disclosed.

It is designed to combine:

• High hardness
• Long-lasting edge retention
• Sharp cutting performance
• Greater corrosion resistance than traditional carbon steel

The blades are hardened to approximately HRC 62–63.

However, hardness alone does not determine the quality of a knife.

Heat treatment, blade geometry, sharpening, balance, and the skill of the user all contribute to its true performance.

These ultra-thin knives represent an attempt to combine the traditions of honyaki construction with a modern and highly specialized approach to blade geometry.

Sakai has been one of Japan’s most important centers of blade production for centuries.

Traditional Sakai knife making is based on a division of specialized skills. Different craftspeople may be responsible for forging, heat treatment, sharpening, polishing, handle fitting, and final finishing.

A finished knife is therefore not simply a manufactured object. It represents the accumulated experience of multiple specialists and the knowledge passed down through generations.

Shiroyama Knife Workshop continues this tradition while also exploring designs that do not simply reproduce familiar forms.

The two knives introduced in these videos reflect that approach. They are rooted in traditional honyaki craftsmanship, yet pursue a distinctive cutting experience through extreme thinness and lightness.

We sincerely thank Japanese Food Technology Channel for taking the time to examine, use, and share these knives with viewers on YouTube.

These videos were not sponsored, commissioned, or produced in collaboration with KIREAJI. KIREAJI was not involved in their planning or production. The reactions, opinions, and observations shown in the videos are those of the channel and its participants.

We are grateful that the craftsmanship, design, and performance of these highly specialized knives have been introduced to a wider audience.

Choosing a handcrafted Japanese knife online requires trust.

Customers outside Japan may not have an opportunity to hold the knife, examine the blade directly, or speak face-to-face with the craftspeople who made it.

Photographs and specifications can provide essential information, but they cannot completely convey how a knife feels and behaves during actual use.

These videos help bridge that distance.

They allow viewers to see not only the appearance of the knives, but also the qualities that become visible only through movement: how the blade enters food, how it responds to the hand, and how its geometry affects the cutting experience.

At KIREAJI, our purpose is not simply to sell Japanese knives.

We aim to connect people around the world with the craftspeople, techniques, knowledge, and values behind each blade.

We believe that understanding a knife’s purpose and limitations is just as important as appreciating its beauty and sharpness.

Super Steel Honyaki Yanagiba 300 mm — Ultra Thin

• Mirror polished on one side
• Approximately 1.8 mm thick
• Designed for highly controlled sashimi slicing
• Recommended for experienced users

Super Steel Honyaki Mukimono 180 mm

• Mirror polished on both sides
• Approximately 1.9 mm thick
• Designed for precision vegetable work
• Recommended for experienced users

A handcrafted knife can be admired through photographs. Its finish, proportions, and visual details can all be appreciated before it is ever used.

However, its true character appears through movement.

It appears in the way the blade enters food, responds to the user’s hand, supports a particular technique, and leaves a clean cutting surface behind.

These two ultra-thin honyaki knives are highly specialized tools. They are not intended to replace every knife in the kitchen, nor are they suited to every user.

Their significance lies in the possibilities they explore.

They show how the traditions of Sakai knife making can be preserved while still allowing craftspeople to pursue new ideas, new geometry, and a different relationship between the blade and the hand.

We hope these videos offer a deeper understanding of the two knives, the techniques they support, and the craftsmanship that made them possible.