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Updated: 22 Apr 2021

Antique Japanese Sword
Shirasaya Katana
Unsigned Gassan Sadayoshi
NTHK Kanteisho Certificate


DELIVERY TIME : Approx. 1-1.5 months
*There might be delay in shipment depending on countries

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

INCLUDED : NTHK Kanteisho Certificate, Shirasaya Case, Traditional Sword Carrying Case , Sword Maintenance Kit, Full Exportation Support

Category Katana (SHIN SHIN TO)
Age Tenpo era(Late Edo period:1831-1845)
Swordsmith Attributed to Gassan Sadayoshi ( 月山貞吉: Unsigned)
Certificate NTHK Kanteisho Certificate
Location Osaka prefecture
Blade Size Length: 80.4 cm(  31.65 inches)/Curvature: 3.0 cm(1.18 inches)

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

In stock

Antique Japanese Sword Shirasaya Katana Unsigned Gassan Sadayoshi with NBTHK Kanteisho Certificate


This blade is attributed to the work of Gassan Sadayoshi(月山貞吉) by NTHK, which authenticated this blade. According to their appraisal, the blade was made in the Tenpo era(Late Edo period:1831-1845), and the sword was initially unsigned(Ubu Mumei:生ぶ無銘).

Gassan Sadayoshi’s real name is Gassan Yahachiro. He was born in Dewakoku(Yamagata prefecture today) in 1781. In his early career, he learned sword forging technique from his father, Okuyama Yasaburo Sadachika(山弥三郎貞近), who is said to have been a descendant of O-Shu Gassan school.

When Sadayoshi became about 20 years old, he went to Edo city and worked for Suishinshi Masahide as an apprentice. Sushinshi Masahide is known as one of the most skilled and famous swordsmiths at the end of the Edo period(150-200 years ago). After ten years of apprenticeship under Masahide, Sadayoshi moved to Osaka in 1833 when he was 30 years old. He founded Osaka Gassan school there and improved his sword-forging technique even more. Gassan school had been almost disappeared in the early-mid Edo period in the mainstream of Japanese history before Sadayoshi came along, it flourished again because of his effort.

Sadayoshi adopted a son from Tsukamoto family and named him Sadakazu, who later became one of the most high-regarded swordsmiths in the post Samurai period(Meiji era). Father and son spent many years researching traditional Gassan style swords and finally achieved to make Ayasugihada, the signature design of Gassan school. Ayasguhihada looks undulating grain pattern in the Jihada, which resembles a Japanese cedar grain.

Gassan Sadayoshi died at the age of 71 in the third year of the Meiji era(1870). His son, Sadakazu, preserved the tradition of Gassan, and he passed it down to Sadakatsu. The Gassan school has been running for the 6th generation. The current Gassan alive is Gassan Kazutoshi, and his son is Gassan Sadanobu.
They still keep forging traditional Japanese swords in Nara prefecture.

We are confident you will appreciate this gorgeous long blade with heavy curvature. When you take a closer look at the blade, you can easily see the beautiful Ayasugi Hada.


【Blade 】
Cutting Edge Length(Nagasa)80.4 cm(  31.65 inches)
Curvature(Sori) 3.0 cm(1.18 inches)

The crystalline structure which forms along the cutting edge of a blade as a result of the hardening process
visible steel surface pattern created by folding and hammering during forging process

【Other details】

NakagoNakago is the hilt 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 PaperNTHK Kanteisho Certificate for the blade

NTHK, also known as NPO Nihon Touken Hozon Kai, is the oldest organization for sword authentication of Japanese swords in modern times. It was established in 1889 during the post-Samurai era. They authenticated the blade on Sep 20th in the second year of Reiwa (2020).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 : Iwate 278491
 The Board of Education in Iwate prefecture issued a registration paper for this sword . In order to obtain this paper, the sword needs to be traditionally hand forged. With this paper, its owner can legally own an authentic Japanese sword in Japan. This paper will need to be returned to the board of education when the sword being shipped abroad but you can receive a copy of it. 


【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 300 Japanese swords 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. 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, EUR or GBP. The price is set in Japanese Yen. Prices in other currencies are automatically calculated based on the latest exchange rate.

  We have shipped authentic Japanese swords to the USA, Canada, Mexico, Australia, UK, Germany , France and Hong Kong. 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 either EMS or FedEx(USA, Australia, Canada).

  We normally ship by EMS(Express Mail Service) provided by Japan Post. When we receive an order from the USA, Australia or Canada we will use FedEx instead as EMS temporarily stops shipping from Japan to those countries due to COVID-19.

  We will send you a tracking number for your order as soon as we hand it to the post office/FedEx. 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.

  *Please keep in mind that due to the spread of COVID-19, there might be delays in shipping. If you like to know the detail about shipping, please feel free to ask us.

【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.

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. When you purchase a Japanese sword from us, you can get a Free sword maintenance kit, which appears in this video.




In stock

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