Antique Japanese Sword Wakizashi Attributed to Koretoshi with NTHK Kanteisho Certificate
【Description】
Summary
This blade was attributed to Koretoshi (是寿), who was the second son of the renowned first-generation Chounsai Tsunatoshi (長運斎綱俊). Tsunatoshi was widely recognized as a genius swordsmith of the Bizen-den tradition during the Shinshinto period in Edo. Koretoshi was a disciple of Suishinshi Masahide (水心子正秀), and his real name was Kato Sukeichiro. Initially, he signed his works as Koretoshi (是寿), later changing his name to Koretoshi (是俊) while maintaining the same pronunciation.
After his father Tsunatoshi passed away, Koretoshi officially inherited the name of the second-generation Tsunatoshi in 1856. Therefore, this sword was created just before he assumed the name “Tsunatoshi.”
Koretoshi served as an official swordsmith for the Ito clan of Hyuga. Among his disciples was Koyama Munetsugu, and his brother, Ishido Unju Korekazu, was an official swordsmith for the Tokugawa shogunate. As the head swordsmith of a major school, he played a significant role in continuing the legacy of his father.
About the First-Generation Chounsai Tsunatoshi
The first-generation Chounsai Tsunatoshi was born in 1798 in Yonezawa, Hashu Province (modern-day Yonezawa City, Yamagata Prefecture). His father was Izumi no Kami Kunihide. Born into the Kato family, he was the younger brother of Kato Tsunahide, and his real name was Kato Hachiro.
Tsunatoshi served the Yonezawa Uesugi clan, a powerful feudal lord in what is now Yamagata Prefecture. Early in his career, he moved to Edo to refine his sword-forging techniques under Suishinshi Masahide, one of the most renowned swordsmiths of the late Edo period. Records also indicate that he forged swords in Osaka and Kumamoto, though his primary workshop was in Azabu, Edo (modern-day Tokyo).
By 1823, Tsunatoshi had settled in Edo, where he created most of his work. He established a respected swordsmithing school and resided in a house provided by the Uesugi family, from whom he also received a stipend. In the first year of the Bunka era (1804), he was granted the honorary title of Chounsai (長運斎), a title he later passed on to his son Koretoshi (the second-generation Tsunatoshi) in 1856, adopting the new title Chojyusai (長寿斎), which means “long life” in Japanese.
Tsunatoshi’s school flourished during the late Edo period, training many swordsmiths who would go on to achieve historical significance, including Koyama Munetsugu, Takahashi Naganobu, and Ishido Korekazu. He excelled in the Bizen-den tradition, particularly in forging swords with Choji Midare Hamon, an irregular, wavy tempering line. His work was so highly regarded that some consider the Tsunatoshi school to have surpassed even that of Suishinshi Masahide in the Bizen-den tradition.
Tsunatoshi passed away at the age of 66 in December 1863, leaving behind a legacy of masterfully crafted swords for high-ranking samurai in Edo. As one of the top-tier swordsmiths of the late Edo period (Shinshinto era) and the head of a prosperous school, his influence endured through his students and descendants. The craftsmanship Koretoshi inherited from his father is evident in this katana, reflecting the excellence of the Tsunatoshi school.
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The school Tsunatoshi belonged to flourished at the end of the Edo period, training many swordsmiths who later became historically significant ones, such as Koyama Munetsugu, Takahashi Naganobu, Ishido Korekazu. Tsunatoshi excelled at forging Bizen-Den tradition swords with Choji Midare Hamon, an irregular, wavy tempering line. Most of Tsunatoshi’s work reflects Bizen Den (One of the Five Japanese sword-forging traditions). In terms of Bizen Den tradition swords, it is said that Tsunatoshi school surpassed Suishinshi Masahide school.
Tsunatoshi died at the age of 66 in December 1863 after creating many great swords for high-class Samurais in Edo city. He is categorized as one of the top-tier swordsmiths during the late Edo period (SHIN SHIN TO era). And, he was the head of the prosperous school at the end of the Edo period. You can see excellent craftsmanship Koretoshi inherited from his father in this Katana.
*Please keep in mind that there are a couple of Kitae Kizu on the blade. If you like to see the detailed condition, please feel free to contact us.
【Blade】
Cutting Edge Length(Nagasa)：38.5 cm (15.1 inches)
Curvature(Sori)：1.0 cm (0.39 inches)
Hamon：
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.
Koshirae：Koshirae is the mounting of the Japanese sword. There are several parts that consist of Koshirae such as Saya (Scabbard), Tsuka (Handle), Tsuba (Handguard).
Fuchi-Kashira：A pair of matching sword fittings that cover the upper and bottom parts of its sword hilt.
The design of this Fuchi Kashira (縁頭) features a scenic landscape with thatched cottage, a tree, and a small bird. These traditional houses, thatched-cottage, reflect the rural lifestyle of Edo-period Japan (1603–1868). Such homes were common in farming villages and evoke a nostalgic, peaceful atmosphere. The small bird, possibly a plover (千鳥, chidori), is a common motif in Japanese art. Plovers are known for their resilience against harsh coastal waves, symbolizing perseverance and strength—qualities highly valued by samurai.
Tsuka and Menuki：Tsuka is the handle of the Japanese sword and Menuki is its decoration.
Tsuba and Habaki：Tsuba is the handguard for the Japanese Sword and Habaki is the equipment to make the blade not touch its scabbard inside. It prevents the blade from getting rusty and chipped.
The design of this tsuba depicts “Ryūsui Zakura” (流水桜), a motif featuring cherry blossoms floating on flowing water, also known as “Sakuragawa” (桜川). In Japanese art, flowing water is often depicted alongside flowers and landscapes, and it is common to combine multiple motifs to create a harmonious design.
This motif symbolizes continuity and auspiciousness, representing the idea that new beginnings never cease, bringing ongoing prosperity. Additionally, it is sometimes interpreted as a scene of spring passing away, as fallen cherry blossoms drift along the water, evoking a sense of transience and seasonal change.
Kozuka：Kozuka is a small knife stored in Kozuka Hitsu (groove of the sheath of the Japanese sword).
Saya：Saya is the scabbard for the Japanese sword.
This Saya is covered with black lacquer. Due to its high waterproof effect, lacquer has been used since ancient times in Asia. The blade of a Japanese sword is made of iron, and moisture is the greatest enemy of iron. For the purpose of carrying the blade without degrading it, people devised a method of coating the scabbard with lacquer. To prevent not only moisture but also rain and snow from penetrating the inside of the scabbard, it was necessary to apply multiple layers of lacquer. The Nushi (塗師, lacquerers) was born precisely because advanced techniques were required to handle the complicated processes.
Authentication Paper: NTHK 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 February 16th 2025. 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 : Osaka 77992
The Board of Education in Osaka prefecture issued a registration paper for this sword. It is called Jyu Ho Token Rui Torokusho (銃砲刀剣類登録証). 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.
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【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 1000 Japanese swords for the past few years (～2025) 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.
【Shipping】
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.
【Review】
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.
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