¥ 40,700 Tax included


UL Framed Backpack for Long Hikes

Our largest framed backpack, ONE, has been sold only by custom order* to meet each hiker’s specific preference of materials and colors. From this season, we will start selling the regular, ready-made version of ONE to make it widely available for customers.

We offer five sizes of torso lengths and four sizes of hip belts for each hiker, and a uniquely designed X-shaped carbon frame fits your torso comfortably and lets you move with ease. The ONE will always offer you comfortable hiking in the rocky sections, ridges with chains, or steep uphills in the Japanese hiking trails.

The front pocket is made of our new BLACK UHPE Fine Grid, a proprietary fabric that uses 200 denier high-density nylon with extremely tough ultra-high molecular weight polyethylene ripstop fiber** woven at 2mm intervals. Of all the fabrics we use for our backpacks, it is the most tear-resistant yet super light and strong.

To keep it light, only the front surface has been treated with a durable water-repellent, whereas the back is not coated. Use a pack liner or waterproof stuff sack to keep your items inside dry. Being non-coated means that the fabric is highly resistant to deterioration from hydrolysis and general use.

*Our custom order version ONE will continue as ONE Custom Edition.

**Also known by trade names such as Dyneema or Spectra. It is an ultra-high molecular weight polyethylene material that is extremely strong and lightweight.


  • Gray
  • Elm
  • Black


Made in Toyooka, Japan

Size 45cm 535g (Without Accessories)
Size 48cm 536g (Without Accessories)
Size 51cm 538g (Without Accessories)
Size 54cm 565g (Without Accessories)
Size 57cm 567g (Without Accessories)
70D HT PC Coated Ripstop Nylon 106g/㎡
30D HT Silnylon 46g/㎡
Front Top Pocket:
BLACK UHPE Fine Grid 128g/㎡
Front Pocket: BLACK UHPE Fine Grid 128g/㎡
Back Panel: 3D Mesh
200D HT PC Coated Oxford Nylon 144g/㎡
Bottom: X-Pac VX21 203g/㎡
​​Zipper: YKK #5 Coil Zipper
​​Frame: Carbon Fiber
Back Pad
Reflectable Bungee Cord
Repair Tape
Torso Length | 45 / 48 / 51 / 54 / 57cm
Hip Belt | XS / S / M / L

Product Story 1

For Longer Hikes

Akira Natsume, Yamatomichi Founder

Do we really love hiking? Are we fully prepared to start up our own business?

In order to find the answer to these questions, my wife and I hiked the John Muir Trail in Virginia, the USA in 2010. Consequently, we realized that we loved hiking so much and decided to quit our jobs and start Yamatomichi. We also realized that Japanese trails are quite different from the ones in North America.

Read more

The John Muir Trail is very well maintained, but unlike in Japan, rocky sections, ridges with chains, or steep uphill sections are rare. This means that in North America, a backpack is less likely to get scratched by rocks or branches that make holes, even when made from ultra-thin fabric. Also, the items in mesh pockets were unlikely to drop out accidentally on these gentle trails. And since the weather in North America is dry with little rainfall, you are less troubled by sweat even when a closed-cell foam pad directly touches your back or the pack’s back panel is not made from some kind of mesh material.
At the time, I realized that the ultralight hiking gear I was using back then was designed specifically for the American climate, environment, and trail conditions.
When my wife and I were about to start Yamatomichi, no ultralight backpack taking into consideration the conditions of the Japanese trails existed.
Even if the ultralight movement originated on the Californian trails, I realized that I did not have to just copy what was happening in the US, but I could use the ultralight theory and match with the conditions of the Japanese mountains to create a unique backpack made specifically for ultralight hiking here in Japan.
As we started Yamatomichi as a very small brand, we were super flexible and I decided that the ONE backpack should be a made-to-order, semi custom-made item that no other mass-production maker could match.
That’s why after ordering, still, our customers need to wait for several months before receiving the finished pack. But I firmly believe that each hiker will find the wait worthwhile and excited to become the owner of his or her unique one-of-a-kind backpack.
It’s been years since we released ONE but it is still one of our core products. There have been many small modifications and upgrades and the robustness and overall durability of the pack have improved since our first version.
So for anyone setting out on a longer hike with a need to carry a somewhat substantial amount of gear, ONE is still the backpack I recommend. (2017)

Product Story 2

Behind the Scene: BLACK UHPE

Akira Natsume, Yamatomichi Founder


It has been more than five years since we started the development of our proprietary BLACK UHPE, and more than seven years if we go back to the point when we learned about Honeywell, the American company that made the Spectra yarn used in the UHPE fiber. We eventually manufactured the fabric in Taiwan, and all in these years, we experienced how difficult and time-consuming it can be to develop a proprietary fabric. Let me share the story.

Read more

The BLACK UHPE is not the only fabric that we developed by ourselves: “100% Merino” and “70 Denier HT PC Coated Ripstop Nylon” are proprietary and it took quite a long time to complete any of these. There are always challenges in the production and even after completion and we are very grateful to the companies who have supported us in our journey towards even better fabrics.

Even Lighter, Stronger

We initiated the development of BLACK UHPE with a study of the toughest weave structure. We analyzed many sample fabrics to define the best method to make a strong, durable, yet lightweight fabric.

After repeated trials, we concluded that the simple, plain-weave, and fine-grid ripstop structure makes the fabric strong. Then, how thick or fine the yarn should be? Is it 50 or 70 deniers? Perhaps 100? How about 200 deniers?
Generally, the lower a denier count is, the lighter a fabric will be. Yes, the fabric became lighter to a certain degree by lowering the denier count, but it was not a dramatic weight reduction. On the other hand, our test showed that the fabrics with a lower denier count showed a marked decrease in strength. After repeated prototyping and testing, we defined that 200D provided an outstanding balance of lightness and strength.

Plant-based Bio-polycarbonate Material

We initially tried a hydrolysis-resistant polycarbonate coating and applied it to the backside of the fabric. The coating is usually made from polyurethane, which tends to be hydrolyzed and decomposed within approximately 10 years, which is a backpack’s virtual lifetime. Therefore, we needed a hydrolysis-resistant polycarbonate material.

Our idea was to adopt the plant-based bio-polycarbonate coating, but it turned out to be unsuccessful at first because UHPE was so heat-sensitive that the general coating method at high temperatures resulted in the melting of the fabric. On the other hand, it was technically impossible to apply the high-quality coating at low temperatures.

How can we properly coat the UHPE? We, together with the coating agent maker, discussed countless times with the Taiwanese fabric manufacturer. The backside coating was a tough issue and took us two years to reach the sad conclusion. The fabric manufacturer’s answer, unfortunately, was that the coating cannot be technically applied on the fine, 2mm grid UHPE ripstop fabric. According to what they said, the coating on a 4mm grid, instead of 2mm, was possible because 4mm was wide enough for the coating to be applied. We were very depressed by this conclusion but had to come up with the next move: non-coated material.

Non-coated Fabric

Before this coating issue became apparent, the purpose of the coating was to enhance the water-resistance of the backpack, which at least was our understanding. However, as many hikers experienced, even if the fabric is coated, when rainy, it tends to absorb water, and the entire backpack gets wet, thus the items inside become moist. We thought that if the items inside get wet by rain with or without the coating, the coating is not essential if not meaningless. Additionally, the coating can cause the weight gain of the fabric, which means that the weight can be lighter if the fabric is uncoated.
However, the meaning of the coating was much more profound than we thought.

Why do fabrics have coatings? Our test showed that without coating, the edges of the cut fabric are likely to be frayed. A backpack made of non-coated fabric usually develops frays at the stitches, and eventually, the whole backpack breaks down.
Then, how can we make a backpack with non-coated fabric? Our answer was to use a laser cutter to cut the fabric. By cutting the non-coated UHPE fabric with a laser, the edges melt and harden, preventing frays.

Proprietary Water/Oil Repellent Coating

We eventually had to give up the water-resistant coating on the back after many trials and errors as described above, but the surface water/oil repellent coating was so crucial in outdoor activities where stain resistance is necessary that we had to continue the development. The proprietary surface coating, however, was equally a challenging issue because it also requires a high temperature when applied, which may damage the fabric.

We searched the global leading companies of the oil/water repellent, one of which turned out to be Daikin in Japan, the major air conditioner company. We contacted them and got to know a good person in charge, who helped us develop the water/oil repellent that can be applied at low temperatures. In the mass-production process, problems occurred, and each time we solved them. It took us about a year to complete the development of the water/oil repellent for our specific needs.

From the initiation of development to mass production, it took a lot of time and effort. Now, we are happy to announce that our proprietary BLACK UHPE is finally ready.

Form and Function

X-shaped Frame Fits Your Back

Located in the back of the pack is a uniquely designed X-shaped carbon frame that fits your torso comfortably and lets you move with ease.

Flexible Load Control

Conventional large-volume backpacks are designed to distribute the load around your waist. However, ONE’s X-shaped carbon frame, waist stabilizers, and shoulder lifters allow full control of the load distribution to fit your needs to direct the load to your waist or upper body, achieving the best load balance for each of you.

*The above function is enabled by the highly flexible carbon frame. But please note that the carbon frame itself is not so strong, so our recommended comfortable maximum load for ONE is 11 kilograms.

Load Distribution on the Upper Torso

When encountering a steep uphill or rocky terrain, free your waist to distribute the load on your upper torso, so that you can walk comfortably using the entire lower part of your body.

  1. Loosen the waist stabilizer straps.
  2. Tighten the shoulder straps to keep the backpack closer.
  3. Tighten the shoulder load lifters.

Load Distribution on the Waist

When getting tired, distribute the load on your waist to alleviate the upper torso fatigue, allowing you to go on walking further. We also recommend the load to be distributed on your waist on flat terrain.

  1. Slightly loosen the shoulder straps.
  2. Tighten the waist stabilizer straps to keep the carbon frame close to your waist.
  3. Tighten the shoulder load lifters to keep the pack closer to your back. (Do not pull too tight.)

Highly Expandable

Our ONE is perfect for long hikes for many days. You can be creative and use the top strap, bungee cords and bottom attachment loops to carry even more.

Anatomy of ONE

How to Attach the Hip Belt

  1. Please make sure the hip belt is correctly positioned.
  2. Insert the hip belt through the attachment area.
  3. Attach the center Velcro of the hip belt to the body, which also has the Velcro side.
  4. Pass the hip stabilizer straps through the plastic parts of the body.

Packing Tips

In the below section, we will show you a packing example in the no-snow season from one of our good friends.

The best way to pack the ONE depends on each hiker. It depends on when, where, why, and how long you hike. Below is just one example of how you could pack the ONE.

*For the reasons below, it is recommended to pack a sleeping bag directly, without its stuff sack:

  • By packing without the stuff sack, the fill power of the sleeping bag stays fresh.
  • The softness of the sleeping bag enhances the comfort around the hip.
  • The bottom part becomes softer and makes it easier to access the water bottle in the side pockets.
  • The sleeping bag swells and fills the gap inside the pack, thus improving the stability.
  • The light sleeping bag is allocated at the lower part, while the heavy items are at the upper part, providing a good load balance and comfort.


The ONE uses the 70D HT PC Coated Ripstop Nylon for the main body, and BLACK UHPE Fine Grid for the front pockets; both fabrics are proprietary.


The new BLACK UHPE Fine Grid is our proprietary fabric that uses robust 200 denier high-tenacity nylon with extremely tough and light ultra-high molecular weight polyethylene (UHPE or UHMWPE) fiber* woven at 2mm intervals as a ripstop.

Of all the fabrics we use for our backpacks, it is the most tear-resistant yet super light and strong.

To keep it light, only the BLACK UHPE’s front surface has only been treated with a durable water-repellent treatment, whereas the backside is not coated. Use a pack liner or waterproof stuff sack to keep your items inside dry. Being non-coated means that the fabric is highly resistant to deterioration from hydrolysis and general use.

*The UHPE fiber is made of an ultra-high molecular weight polyethylene material with excellent strength and lightness. The Dyneema and Spectra are made of the same UHPE fiber and generally conceived as white, but we adopted the black yarn.

The laser cutter makes it fray-proof by melting and hardening the cut edges.

Material: 200 Denier Ultra High Molecular Weight Polyethylene (UHPE) Fiber, 200 Denier High-tenacity Nylon
Coating: C6 DWR (Durable Water Repellent)
Weight: 128g/㎡

In-house test results*:

  • Tensile strength (JIS L1096A): 180kg (vertical), 160kg (horizontal)
  • Tear strength (JIS L1096D): 20kg (vertical), 17kg (horizontal)

*Variations may occur according to the actual production lot.

70D HT PC Coated Ripstop Nylon

This 70 denier HT (high-tenacity) ripstop nylon fabric is our proprietary material with enhanced strength and durability compared with conventional nylon. The surface is DWR (durable water repellent) finished, and the backside is polycarbonate coated, achieving a much better anti-hydrolyzation performance than regular polyurethane-based fabrics. The results of the Tropical Test, aka Jungle Test, in which the fabrics are left in a machine with 95% humidity, temperatures at 70°C for ten weeks, showed that the new material ​will not significantly deteriorate for 10 years.

Material: 70 Denier High-tenacity Nylon, Polycarbonate Coating
Coating: C6DWR (Durable Water Repellent)
Weight: 106g/㎡

In-house test results*:

  • Tensile strength (JIS L1096A): 97kg (Vertical), 64kg (Horizontal)
  • Tear strength (JIS L 1096D): 7kg (Vertical), 4kg (Horizontal)
  • Water pressure resistance (JIS L1092B): 4079mm

*Variations may occur according to the actual production lot.

Comparison Chart of Fabrics

The blue number shows the weight (gram per square meter), and the black number indicates the tear strength (kilogram). Overall, the BLACK UHPE is lightweight but has excellent strength.


We offer five sizes of torso lengths and four sizes of hip belts. To define the size correctly, we recommend that you try on the product before purchase.

*The torso length refers to the length of the back bone, which we define as the length measured from the C7 vertebra to the hipbone.

45cm 48cm 51cm 54cm 57cm
HIP BELT / 腰骨周囲長(cm)
72-79 78-85 84-92 91-100

*The hip belt size is not your waist size. To define the hip belt size correctly, make sure you wrap your tape measure around your hipbone.
If you can’t decide between two sizes of the hip belt, we usually recommend the smaller size so that you can tighten it firmly.

How to Measure Your Torso

Decide your torso length based on the jutting, upper edge of the pelvic bone at each side of your hipbone.

  1. Find the jutting of each side of your hipbone, and align your pants’ waistband on the juttings. The level of the waistband is where the hipbone should be.
  2. Find the backbone and extend the tape measure from the waistband to the back of your neck.
  3. Slightly tilt your head forward to find the bump of your back neck (7th cervical vertebra, or 7C vertebra) and measure the distance from the waistband to the 7C vertebra.

*The length from the edge of the waistband to the 7C vertebra is defined as the torso length. To define the hip belt size correctly, make sure you wrap your tape measure around your hipbone.

Size Guidance

Unit: cm
背面長 / Torso Length 45 48 51 54 57
身長 / Height 150-160 158-170 168-175 173-180 178-190

*The above should only be used as a rough guide. Please note that torso length may vary depending on your body shape. Wrap your tape measure around your hipbone. Your hip belt size cannot be determined by your weight and height.


Please Note

The ONE is water repellent finished, but not water-resistant. The pack cover is useful but does not make your backpack waterproof. Use a pack liner or Ziploc bags to keep your items inside dry.

Care Instructions

  • Hand-wash only. Do not machine wash.
  • Submerge the product in lukewarm water with a correct amount of neutral detergent, and hand-wash it.
  • Do not bleach. Do not use fabric softener.
  • Remove any optional parts such as pads and carbon rods before washing.
  • Wash off any noticeable stains or smudges with a washing brush or soft sponge.
  • Rinse well so that no detergent remains.
  • Drain the backpack with the mouth down. Keep dry in a shade.
  • Store in a dark, well-ventilated place.
  • Do not iron.


  • We only accept payment by credit card. We currently do not accept payment via bank transfer from overseas accounts.
  • We accept the following Credit Cards: Visa, Master, American Express, and JCB.
  • To download your receipt, please click the link included in the Dispatch Notice, which we will send by email as soon as the items are dispatched.


We will ship by DHL for overseas customers (excluding China, Hong Kong, Taiwan, Korea and Russia). For customers in China, Hong Kong, Taiwan, Korea and Russia, we will ship by EMS only. Shipping costs vary depending on your country and region.

Size Exchange

  • Overseas customers who need to change the size of their order, should note that the time needed for shipping will vary greatly depending on your country of residence.
  • We only accept exchanges when the item is unused (except for fitting).
  • If you wish to exchange the size of the item, please contact us within seven days of receiving your order.
  • Exchanges can only be made for the same color in a different size.
  • If the size you wish is out of stock, we will suggest a different color.
  • If the product is out of stock, we may simply have to ship the item back to you.
  • All shipping costs to be carried by the customer.
  • We will only send the exchanged item to you, upon receipt of return shipping cost via PayPal.
  • Please be aware that some countries charge customs duties depending on the price of the item.
  • We are unable to answer any questions on local customs. Please contact your local customs bureau.


We accept repairs for all of our Yamatomichi products. For inquiries on repair services including patching the holes, repairing with extra components, or fixing the items damaged over time, please feel free to contact us from the “Repair” section of the SUPPORT page.

Repair Tape

  • For temporary repair, please keep the repair tape in your emergency kit.
  • The repair tape should be patched up on both the front and back sides of the fabric. The tape must be larger than the damaged or torn part of the fabric.
  • If you round the edges of the patch, it will last longer.
Restock Alert



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