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Updated: 21 Jul 2024

Antique Japanese Sword Katana attributed to Seki Shu Naotsuna


DELIVERY TIME: Approx. 1-1.5 months
*We ship from Tokyo, Japan. There might be delay in shipment depending on countries.

USA, Canada, Mexico, Germany , Belgium, France, Finland, Hong Kong, Australia
*Please contact us prior to purchase if your country isn’t listed.

INCLUDED: NBTHK JUYO TOKEN Certificate, Shirasaya Case, Traditional Sword Carrying Case, Sword Maintenance Kit, Full Exportation Support

Category Katana (KOTO)
Age Early Nanbokucho period (Early 14th century)
Swordsmith Attributed to Seki Shu Naotsuna (石州直綱: Unsigned)
Certificate NBTHK JUYO TOKEN Certificate
Location Sekishu province (Today’s Shimane prefecture)
Blade Size Cutting Edge Length: 70.8 cm (27.9 inches)
Curvature: 1.5 cm (0.59 inches)

More photos& videos available on request. Please feel free to contact us. 

In stock

Antique Japanese Sword Katana attributed to Naotsuna with NBTHK JUYO TOKEN Certificate



 This blade is attributed to Sekishu Naotsuna (石州直綱), whose maker’s name lasted a few generation during the Kenmu-Oei era (1334-1428: early Nanbokucho-early Muromachi period). Sekishu is the province located in today’s Shimane prefecture. And Dewa is the name of the village.

  The first-gen Naotsuna is said to have been one of the ten apprentices of Masamune. Masamune is one of the most famous swordsmiths in Japanese history. Those ten apprentices are called Masamune Jittesu (正宗十哲).

 The first-gen Naotsuna originally resided in Sagami province (today’s Kanagawa prefecture) to master SOSHU DEN tradition from Masamune. Then, Naotsuna moved to Sekishu (Today’s Shimane prefecture). 

  When Sadatsuna was active in the Nanbokucho period, Japan was tumultuous because the imperial court was split into two sides(south and north). There were many conflicts, and many Samurai were deployed. And Sadatsuna must have dedicated himself to forging high-quality blades for those Samurai who fought in battles.

 Sekishu is also known as Iwami koku and it was famous for producing the high-quality carbon steel for the Japanese sword. We presume Sadatsuna had easy access to this exceptionally great carbon steel to create his swords.


Hamon (刃紋)& Kitae (鍛)

 Its Hamon is mainly Notare and also mixed with Gunome. It has activity of Nie, Hotsure, Kinsuji and Sunagashi. Its Kitae is Itame with Mokume. Its Hada isverry visible and Nie is also found in Ji part. It also has Chikei.


Soshu Den

 Swordsmiths residing in Soshu province (Today’s Kanagawa prefecture) used a particular sword-forging tradition called Soshu Den. And, Shimada school also used this tradition to forge blades. Shoshu Den was born in the middle of the Kamakura period (mid 13th century). Back then, the Yamato and Yamashiro traditions were highly developed, and there were a few renowned swordsmiths from those regions. However, the sword-forging practice was in its infancy in the Kanto area, where the Soshu region was located.

 At the beginning of the Kamakura government, which was established in 1185, the first Shogun, Minamoto Yoritomo, prioritized making a lot of rules to have its political stability. And he couldn’t afford to hire swordsmiths within the same region or train them. Therefore, the Kamakura government originally ordered weapons to the swordsmiths in the other areas, such as Yamato and Yamashiro.

 But, since the government was established, the demand for weapons increased exponentially in the government, and they had to figure out how to meet those demands from Samurai who served Kamakura shogunate. Then, the 5th head of the Shogun, Hojo Tokiyori, invited two renowned swordsmiths from other parts of Japan. They were Awataguchi Kunitsuna from Yamashiro province and Bizen Saburo Kunimune from Bizen province. And the 7th-gen Shogun Koreyasu Shino also invited Fukuoka Ichimonji Sukezane from Bizen province.

 It is said that those three swordsmiths played an essential role in creating the Soshu Den and making the foundation of the Soshu Den. Also another famous figure in the Soshu den is Intou Kunimitsu, an adopted son of Awataguchi Knitsuna. And Kunimitsu passed his excellent craftsmanship to Yukimitsu, his apprentice. And Masamune, one of the most famous swordsmiths in Japanese history, was an apprentice of Yukimitsu.  And Masamune was the one that brought Shoshuden to nationwide fame. The tradition Masamune completed became an example of other swordsmiths who learned Soshu Den. Also, Soshu Den influenced many renowned swordsmiths during the Koto- Shinto era. One of examples is Inoue Shinkai from Osaka and Suishinshi Masahide from Edo.



 This blade is appraised as a JUYO TOKEN (重要刀剣) issued by NBTHK (Nihon Bijutsu Touken Hozon Kyokai: 日本美術刀剣保存協会). This authentication paper was only given to authentic Japanese swords, exceptionally well preserved and of high quality with artistic value. JUYO is one rank higher than Tokubetsu Hozon. To be eligible for a Juyo Token, it needs to be appraised as a Tokubetsu Hozon Token first. It is extremely rare for an antique Japanese sword to be appraised as JUYO TOKEN, and it is highly desirable among Japanese sword collectors.


【 Blade】
Cutting Edge Length (Nagasa): 70.8 cm (27.9 inches)
Curvature (Sori): 1.5 cm (0.59 inches)


The crystalline structure which forms along the cutting edge of a blade as a result of the hardening process.
Jimon (Jihada):
Visible steel surface pattern created by folding and hammering during forging process.


Kissaki: Kissaki is the tip of the Japanese sword.


Nakago: Nakago is the tang of the Japanese sword.

 Japanese swordsmiths left the black rust on the tang because it prevents red rust while the tang is in its handle. And the discoloration of the tang was created over time, and it is a great indicator for a Japanese sword specialist to estimate when the sword was forged.



Habaki: Habaki is the equipment to make the blade not touch its scabbard inside. It prevents the blade from getting rusty and chipped.


Authentication Paper: NBTHK JUYO TOKEN Certificate for the blade (No. 14605)

  NBTHK, also known as Nihon Bijutsu Touken Hozon Kyokai (the Society for the Preservation of the Japan Art Sword), is one of the oldest Japanese sword appraising organizations in modern-day Japan. They authenticated the blade on Dec 15th in the 2nd year of Reiwa (2020). They appraised it as JUYO TOKEN, the blade exceptionally worth preserving for Japanese society. The purchaser will receive this original certificate as well. We can also translate what is written into English and make a PDF file for your record if you request.


Registration Number: Tokushima 859
  The Board of Education in Tokushima prefecture issued a registration paper for this sword. It is called Jyu Token Rui Torokusho (銃刀剣類登録証). Bunkacho (The Agency for Cultural Affairs) acknowledges a Japanese sword with this paper as a work of art.
The sword needs to be traditionally hand-forged and made of Tamahagane carbon steel to be registered in the system. With this paper, its owner in Japan can legally own an authentic Japanese sword. Based on this registration number, we will apply for its export permit.
This paper will need to be returned to the board of education when the sword is being shipped abroad, but you can receive a copy of it. An English translation of this registration paper is available on request.

【About us】
 Samurai Museum is located in Tokyo, Japan, exhibiting antique artifacts related to the Samurai history. Samurai Museum Shop is the place for those who are interested in Japanese culture and craftsmanship. We deal with antique Samurai swords/armor, traditional crafts made in Japan and so on.

Japanese Sword& Export Process
 The Japanese swords we deal with are hand-forged edged swords made in Japan. It was made from the traditional carbon steel called TAMAHAGANE(玉鋼). Samurai Museum is familiar with the proper legal procedure for an antique/ authentic Japanese sword to be exported from Japan. We have sent more than 700 Japanese swords for the past few years (~2024) to amazing owners who appreciate its historical value.

 Each Japanese sword is registered under the Agency for Cultural Affairs and the Board of Education in Japan. They issue a registration paper for each Japanese sword for its owner in Japan to legally possess it. The Japanese sword with its registration paper means it was traditionally hand-forged in Japan.

 To legally export the sword from Japan to other countries, we will have to apply for its permit to the Agency for Cultural Affairs(Bunkacho) and return the original registration paper to the Board of Education. It normally takes around 2-4 weeks to receive this permit after submitting required documents. And we would like you to expect at least 1-1.5 months for your order to arrive at your given address after you ordered. For more detailed info, please click here.

 It is allowed for residents in Japan to own authentic Japanese swords without a special license as long as they come with registration papers. Please feel free to contact us if you are a resident of Japan, whether temporarily or permanently. We will also assist you when you leave Japan and need to obtain the export permit.

【Payment Method】
We accept payment through Stripe (Credit card), PayPal, Apple Pay or ChromePay, all of which are secure payment methods. Also, you don’t need to make an account on Stripe for the checkout. If you prefer other payment method, please contact us. After confirming your payment, we will apply for an export permit. You may either pay in JPY, USD, AUD, CAD,EUR CHF or GBP. The price is set in Japanese Yen. Prices in other currencies are automatically calculated based on the latest exchange rate. 

* If the amount is above 1 million JPY, Stripe or wire transfer will be the only options for payment.

 We have shipped authentic Japanese swords to the USA, Canada, Mexico, Germany , Belgium, France, Finland, Hong Kong, Australia. If you don’t live in these countries and like to order, please contact us first before making a purchase. We offer Free International Shipping as long as we can send antique Japanese swords by EMS. 

 We normally ship by EMS(Express Mail Service) provided by Japan Post. We will send you a tracking number for your order as soon as we hand it to the post office. We will put 100 % insurance on the shipping document without any extra charge. Based on the total amount, there might be a duty tax or other fee for you to pay, depending on the countries. We use package cushioning to protect the item and put it in a PVC pipe, which is one of the most secure packages because of its durability.

 It will normally takes 5-14 days for the item to arrive at your given address after we dispatch it. Time of delivery is estimated as accurately as possible by the carrier but does not take into account any delays beyond our control such as by inclement weather, post office holiday seasons.

* If you live in Australia and like to purchase an authentic Japanese sword, please click here to know the detail.

* If you live in the UK and like to purchase an authentic Japanese sword, please contact us first and click here to know the detail.

 Here is one of the reviews we received from a customer who purchased an authentic Japanese sword from us. For more reviews, please click here.
“My experience overall with the whole process was wonderful. I had many questions about the history and process to purchase these treasures. All my questions were answered very timely and complete. The staff is very knowledgeable and very well versed if any questions do arise.”

【How to make sure the condition】
 Please keep in mind that what you are going to purchase is an antique item. We uploaded high resolution photos for you to check its condition thoroughly. If you like to see more photos with different angles, please feel free to contact us. We will be happy to send them to you so that you can make informed decision. It is essential for us to know that you are happy with your choice of a sword. and we are prepared to use the best of our ability to serve you.

【How To Contact Us】
 Please contact us through email, Facebook Messenger or Live Chat if you have any questions. You can find each icon on the right side of the website. Please click one of them to reach us. We will reply to you within 1-2 business days.

The Art of Nihonto (Japanese Sword)
 Samurai’s history is a profound, eloquent legacy of ancient Japanese warriors in which millions of people worldwide are being fascinated. If you like to find out the art of Nihonto, please click here.

A Guide to Japanese Sword Maintenance
 After acquiring an genuine Japanese sword, it is also important to know how to take good care of it. Here is the special video for you. Mr. Paul Martin, Japanese sword expert, shows you how to give proper maintenance to your sword. By mastering how to clean the Japanese sword, its aesthetic beauty will last forever.

 When you purchase a Japanese sword from us, you can get a Free Japanese sword maintenance kit. It comes with four tools(Choji Oil, Uchiko Whetstone Powder, Peg remover, Oil Applicator). By watching the video instruction above , you can enjoy learning how to maintain your Japanese sword while appreciating it. If  you have any difficulty assembling the sword or cleaning the blade, you can feel free to contact us.







 Thank you for reading all the information on the page. If you have any difficulty choosing the right Japanese sword for you, we will be more than happy to help you find the one that speaks to you the most. Please feel free to contact us.


In stock

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