How accurate is this certificate ?

[Bosco]

Hi, 

 

I just want to know how they determine which generation of Nobukuni for this sword. This is the best picture I could get. Thank you.

 

[Rivkin]

To keep matters fast and simple - its not, the chance of repapering today is 10%.

[Bosco]

4 minutes ago, Rivkin said:

To keep matters fast and simple - its not, the chance of repapering today is 10%.

Thank you, I have the same thinking as well. 
 

For the sword, do you have any comment for it ?. I plan to study on this one with a book. Gotta start somewhere.

[Rivkin]

Treating it as gimei: Around Tembun(?), weak hada, poor polish, hamon suffocated by hadori.

[SteveM]

Looks like Tenshō (天正). 1573-1592.

[Cola]

20 hours ago, Rivkin said:

Treating it as gimei: Around Tembun(?), weak hada, poor polish, hamon suffocated by hadori.

 

How do you see the difference between hamon and hadori in pictures like these? 

[Jussi Ekholm]

I wouldn't necessarily think too negatively about the sword.

 

It is not "THE" Nobukuni lineage but instead quite unknown Buzen Nobukuni. As the signature would be 宇佐住信国 - Usa jū Nobukuni.

[Rivkin]

2 hours ago, Cola said:

 

How do you see the difference between hamon and hadori in pictures like these? 

 

Precisely - if only hadori is seen, it means either that hadori is very heavy or the hamon does not have any nie.

The problem is that some of the photographs are from above, some taken at an angle. Both cases look nearly the same, but if you put the contrast to the max, there is some nie. 

Which suggests its very hadori heavy and most likely its ko nie without any large nie crystals. Otherwise you would see significant difference at different angles.

 

[Bosco]

16 hours ago, Jussi Ekholm said:

I wouldn't necessarily think too negatively about the sword.

 

It is not "THE" Nobukuni lineage but instead quite unknown Buzen Nobukuni. As the signature would be 宇佐住信国 - Usa jū Nobukuni.

This is the comment from dealer, I wouldn’t think it’s a negative at all. But some study would help. I will take more photos once I got it in my hand.

 

”This formidable katana, signed "Usa Ju Nobukuni - August

Day"（宇佐住信国 八月日），dates back to the Tensho era

(Momoyama period, circa 1570s-1580s)—a time of great historical upheaval, including the famous Honno-ji Incident.

The Buzen Nobukuni School served the Ajimu Clan of Usa, but after their downfall by Otomo Sorin in 1582 (Tensho 10), they relocated to Chikuzen under the patronage of Kuroda Nagamasa, forming the Chikuzen Nobukuni lineage. This blade is likely one of the last works of the Buzen Nobukuni school before their transition to Chikuzen.

Its wide mihaba (blade width) and long nagasa (blade length of nearly 2 shaku 5 sun / 75.4 cm) give it an imposing and powerful presence, making it a truly remarkable piece of history. “

[Bosco]

16 hours ago, Jussi Ekholm said:

I wouldn't necessarily think too negatively about the sword.

 

It is not "THE" Nobukuni lineage but instead quite unknown Buzen Nobukuni. As the signature would be 宇佐住信国 - Usa jū Nobukuni.

This is the comment from dealer, I wouldn’t think it’s a negative at all. But some study would help. I will take more photos once I got it in my hand.

 

”This formidable katana, signed "Usa Ju Nobukuni - August

Day"（宇佐住信国 八月日），dates back to the Tensho era

(Momoyama period, circa 1570s-1580s)—a time of great historical upheaval, including the famous Honno-ji Incident.

The Buzen Nobukuni School served the Ajimu Clan of Usa, but after their downfall by Otomo Sorin in 1582 (Tensho 10), they relocated to Chikuzen under the patronage of Kuroda Nagamasa, forming the Chikuzen Nobukuni lineage. This blade is likely one of the last works of the Buzen Nobukuni school before their transition to Chikuzen.

Its wide mihaba (blade width) and long nagasa (blade length of nearly 2 shaku 5 sun / 75.4 cm) give it an imposing and powerful presence, making it a truly remarkable piece of history. “
 

[Bosco]

Since the paper was issued in 1970s. A bit of research and I found the signature was actually dated further back.

[Nihonto student]

Dear Minh,

 

without going into this specific case of attribution, I think it is useful for you to read this article since I think it is the real answer to the title of your post:

 https://web.archive.org/web/20210123052725/https://blog.yuhindo.com/green-papers-no-papers/ 

 

You will find many posts about this argument on the forum... the advice I want to give you is therefore to focus on the study of blades with reliable certification and only when you have gained skills move on to the dubious ones.

 

Regards

Giordy

[Jacques]

Quote

making it a truly remarkable piece of history. 

This kind of sentence is a red flag for me  As the certificate is no longer recognized by the NBTHK, this sword can be considered without papers.

[Shugyosha]

3 hours ago, Nihonto student said:

Dear Minh,

 

without going into this specific case of attribution, I think it is useful for you to read this article since I think it is the real answer to the title of your post:

 https://web.archive.org/web/20210123052725/https://blog.yuhindo.com/green-papers-no-papers/ 

 

You will find many posts about this argument on the forum... the advice I want to give you is therefore to focus on the study of blades with reliable certification and only when you have gained skills move on to the dubious ones.

 

Regards

Giordy

 

As Jussi says, it's not the the big name Nobukuni, so there's no reason to suspect that this paper isn't the genuine opinion of the shinsa panel on the day it viewed the blade - if anything, the paper talks the blade down by ascribing it to the smith working in Tensho. If you read Darcy's article, it emphasises that the bigger then name, the greater the danger with these papers and that they aren't all bad - this is a small name smith and so this one is probably OK.

 

@Bosco - the seller isn't going to tell you that the blade is a piece of junk that you definitely shouldn't buy and using the Sengoku Jidai as sales puff is something that occurs frequently as there's a degree of romance attached to the period that sells swords - but I've just reread your post and it looks like you've already gone for it, so I hope you like it once it arrives.

[Geraint]

Dear Minh.

 

The date on the nakago is Tensho as Steve has pointed out.  Nihonto club is a useful resource but not comprehensive, Hawleys lists several smiths signing this way working between 1350 and 1573.  It is not reasonable to jump to a date based on Nihonto club which contradicts the mei on your sword, rather more likely to be one of the other smiths working in the Tensho period.

Enjoy your sword and your research.

 

All the best.

 

 

[Bosco]

Thank you all for your information. To me I just want to track down who made it and it’s not fake that’s all I care about. It’s a beautiful sword.

I have been trying to track down a second one signed with Usa Ju Nobukuni - 宇佐住信国 . But the only one I can find is in Oita Prefecture from Usa Jingu Shrine or Yusuhara Hachimangu Shrine a Tanto signed 短刀（銘「宇佐住信国」. 
 

I love research and study on new things, Nihonto has always been in my heart. But I never get to learn more. I genuinely asking for advice and opinions. But I’m young… we all started somewhere right ?. 
 

Have a great day guys.

 

 

 

 

“ 大分県には、国指定重要文化財や大分県指定有形文化財の刀剣類が数多く所在し、宇佐神宮所蔵の白鞘入剣や柞原(ゆすはら)八幡宮所蔵の太刀などが知られています。その中で、宇佐などの旧豊前地域と関係が考えられる資料には、短刀（銘「宇佐住信国」）などがあります。”

[Bosco]

On 4/8/2025 at 8:54 AM, Rivkin said:

Treating it as gimei: Around Tembun(?), weak hada, poor polish, hamon suffocated by hadori.

Calling it gimei based on the green paper or a signature you haven’t seen before is quite absurd. I’m new to Nihonto, it’s doesn’t make any sense to me !.

[Bugyotsuji]

2 hours ago, Bosco said:

Calling it gimei based on the green paper or a signature you haven’t seen before is quite absurd. I’m new to Nihonto, it’s doesn’t make any sense to me !.

Minh, it's just his opinion, and he is 'treating it as...', which is a temporary position just to be on the safe side. Green papers were often correct, but often wrong, so their track record is not so good compared to more modern paperwork. Anyway, it is safer to assume a measure of doubt with anything, but keep collecting information in the meantime! 

[Bosco]

42 minutes ago, Bugyotsuji said:

Minh, it's just his opinion, and he is 'treating it as...', which is a temporary position just to be on the safe side. Green papers were often correct, but often wrong, so their track record is not so good compared to more modern paperwork. Anyway, it is safer to assume a measure of doubt with anything, but keep collecting information in the meantime! 

Thank you. I did further detective work and I traced down the second one and only with signature 宇佐住信國 is a Tanto registered in 1972 and currently sitting at OitaPrefecture from Usa Jingu Shrine or Yusuhara Hachimangu Shrine. The green paper for the Katana was given in 1976 and the registration in 1950s. Unless there are more with the same signature otherwise I don’t know how an individual can prove it. On top of that why would they fake a signature that wasn’t exist or known of ?. Please see the registration of the Tanto with Usa Ju Nobukuni. City and shrine checked out. Only 2 out there at the moment with this signature. What if it was once a Daisho ?, since there are only 2 with the same signature. This is my logical conclusion, unless anything else can justify this ?

[Rivkin]

Original question before editing was - is certificate believable? My personal opinion - no, and NBTHK is unlikely to repaper it. BTW, I think with NTHK there is better chance. They use different standards and what I see as a problem for NBTHK will be less of an issue for others. A guess, but its after all a split issue.

Then was a question - what is it then?

I should have said more generally "late Muromachi" because objectively the seller's photographs are not the best. Also, assuming such questions are asked pre-purchase I am trying to emphasize the blade's quality - which is far from outstanding, at least in terms of nihonto aesthetic.

Why? Its a long story which I am not motivated to explain given the manner of inquiry.

 

Good luck on your first blade and have fun studying it and researching other similar examples. Its a nice weapon and I am sure it will lead to many discoveries.

[Bosco]

38 minutes ago, Rivkin said:

Original question before editing was - is certificate believable? My personal opinion - no, and NBTHK is unlikely to repaper it. BTW, I think with NTHK there is better chance. They use different standards and what I see as a problem for NBTHK will be less of an issue for others. A guess, but its after all a split issue.

Then was a question - what is it then?

I should have said more generally "late Muromachi" because objectively the seller's photographs are not the best. Also, assuming such questions are asked pre-purchase I am trying to emphasize the blade's quality - which is far from outstanding, at least in terms of nihonto aesthetic.

Why? Its a long story which I am not motivated to explain given the manner of inquiry.

 

Good luck on your first blade and have fun studying it and researching other similar examples. Its a nice weapon and I am sure it will lead to many discoveries.

My question was how accurate is the certificate with the signature. As far as I know there are only 2 out there with the same signature. 
 

Given the fact that the first Tanto signed Usa Ju Nobukuni - 宇佐住信國 was the only and first registered in 1972. It was displayed at Oita Prefecture Museum “ 第53回 特集展示『五所家刀』後期展示” . 

While the green certificate was given on 1976 so I bet it was the first time they saw such signature. 

 

 

[nulldevice]

30 minutes ago, Bosco said:

My question was how accurate is the certificate with the signature. As far as I know there are only 2 out there with the same signature. 
 

Given the fact that the first Tanto signed Usa Ju Nobukuni - 宇佐住信國 was the only and first registered in 1972. It was displayed at Oita Prefecture Museum “ 第53回 特集展示『五所家刀』後期展示” . 

While the green certificate was given on 1976 so I bet it was the first time they saw such signature. 

 

 

How do you know that tanto you found was the "only and first" tanto signed that way? The NBTHK has had hundreds of thousands of blades pass through their shinsa over the decades and there is no possible way to guess how many Nobukuni signed blades passed through in any given year. We'll likely never have that information in English let alone Japanese for the lower level papers. I would assume there are many more examples of blades with this signature that the NBTHK has record of. There isn't an online index where you can search NTBHK paperwork and only a small portion of papered blades make their way onto the internet where we can search them. 

 

The NBTHK asked that many people with older papers re-submit for a new shinsa just to clarify the very thing we're debating in this thread. Not all old papers are unreliable, but enough are that in order to remove all doubt, you should resubmit for Hozon and get the same attribution.

[Bosco]

14 minutes ago, nulldevice said:

How do you know that tanto you found was the "only and first" tanto signed that way? The NBTHK has had hundreds of thousands of blades pass through their shinsa over the decades and there is no possible way to guess how many Nobukuni signed blades passed through in any given year. We'll likely never have that information in English let alone Japanese for the lower level papers. I would assume there are many more examples of blades with this signature that the NBTHK has record of. There isn't an online index where you can search NTBHK paperwork and only a small portion of papered blades make their way onto the internet where we can search them. 

 

The NBTHK asked that many people with older papers re-submit for a new shinsa just to clarify the very thing we're debating in this thread. Not all old papers are unreliable, but enough are that in order to remove all doubt, you should resubmit for Hozon and get the same attribution.

Yet, none of Nobukuni signed Usa Ju Nobukuni has been sighted out there. Even deep search in Japanese wouldnt show up anything.I'm reaching out to Oita Museum at the moment to track down that Tanto so I can have more information on it. 

Because the green paper said Tensho which is 1573-1592. While the signature and particular one like this one is from Choroku 1457-1460. 

I want to discuss the year it was made and signed. How paper was given to Tensho. Not the condition of the blade. I’m a beginner, what I want to learn is fact and history. Please forgive my English if it sounded offensive to anyone here. 

[Bugyotsuji]

(The old papers suggested Tensho, as Steve says.) Good luck and happy hunting.

With such a regional, even local blade, I agree that there was probably no benefit to anyone by adding a gimei to it, as you say.

[nulldevice]

55 minutes ago, Bosco said:

Yet, none of Nobukuni signed Usa Ju Nobukuni has been sighted out there. Even deep search in Japanese wouldnt show up anything.I'm reaching out to Oita Museum at the moment to track down that Tanto so I can have more information on it. 

Because the green paper said Tensho which is 1573-1592. While the signature and particular one like this one is from Choroku 1457-1460. 

I want to discuss the year it was made and signed. How paper was given to Tensho. Not the condition of the blade. I’m a beginner, what I want to learn is fact and history. Please forgive my English if it sounded offensive to anyone here. 

I mean, there may be 10 more Usa Ju Nobukuni signed blades out there with old and modern papers sitting in collections that we may never see. The NBTHK has records of these and probably the best library of resources and oshigata in existence and we get only a very small glimpse into their world. What we do know is that during the shinsa session, they had reason to assign the blade to the Tensho Nobukuni and we know that they have more resources than just Fujishiro, Hawley, Toko Taikan, etc.. 

 

I hope you can find more information and wish you happy hunting as well. The thrill of tracking down new information is indeed exciting and challenging when dealing with a foreign language that is hard to search if you don't speak it at a decent proficiency level, even with good internet skills. 

 

Edit: Also, if your final goal is to put all doubts aside, a new shinsa is really the best way. The reasons have been beaten to death above.

[Bugyotsuji]

Here are some more Usa Jū Nobukuni to sift through, from the Nihontō Meikan.

 

(cont.)

 

[Bosco]

37 minutes ago, nulldevice said:

I mean, there may be 10 more Usa Ju Nobukuni signed blades out there with old and modern papers sitting in collections that we may never see. The NBTHK has records of these and probably the best library of resources and oshigata in existence and we get only a very small glimpse into their world. What we do know is that during the shinsa session, they had reason to assign the blade to the Tensho Nobukuni and we know that they have more resources than just Fujishiro, Hawley, Toko Taikan, etc.. 

 

I hope you can find more information and wish you happy hunting as well. The thrill of tracking down new information is indeed exciting and challenging when dealing with a foreign language that is hard to search if you don't speak it at a decent proficiency level, even with good internet skills. 

 

Edit: Also, if your final goal is to put all doubts aside, a new shinsa is really the best way. The reasons have been beaten to death above.

 

 

18 minutes ago, Bugyotsuji said:

Here are some more Usa Jū Nobukuni to sift through, from the Nihontō Meikan.

 

(cont.)

 

 
Thank you so much, I will definitely have fun with all this information.

[Nihonto student]

14 hours ago, Shugyosha said:

 

As Jussi says, it's not the the big name Nobukuni, so there's no reason to suspect that this paper isn't the genuine opinion of the shinsa panel on the day it viewed the blade - if anything, the paper talks the blade down by ascribing it to the smith working in Tensho. If you read Darcy's article, it emphasises that the bigger then name, the greater the danger with these papers and that they aren't all bad - this is a small name smith and so this one is probably OK.

 

@Bosco - the seller isn't going to tell you that the blade is a piece of junk that you definitely shouldn't buy and using the Sengoku Jidai as sales puff is something that occurs frequently as there's a degree of romance attached to the period that sells swords - but I've just reread your post and it looks like you've already gone for it, so I hope you like it once it arrives.

Dear John,

 

I agree with your opinion in general, but my answer as specified was not aimed at judging this case, it is only for completeness of information... you have all the experience to make these considerations but Minh does not yet, so it seemed right to inform him of the story behind green papers...for me the key word regarding a possible purchase is "awareness" if you are aware then some choices can be subjective, but you will not regret it.

 

Regarding the blade:

The price is not that low, it does not make me scream at the deal of the year.
The blade is in Japan so as always I see no reason not to have it papered, so I would ask the seller for mediation by paying a deposit  fully refundable if the blade doesn't pass, if the blade pass I would pay the related certification costs + extra for the service (Obviously estimated beforehand) if the seller refuses I would pass.

 

Kind Regards

 

Giordy

 

[Bosco]

6 minutes ago, Nihonto student said:

Dear John,

 

I agree with your opinion in general, but my answer as specified was not aimed at judging this case, it is only for completeness of information... you have all the experience to make these considerations but Minh does not yet, so it seemed right to inform him of the story behind green papers...for me the key word regarding a possible purchase is "awareness" if you are aware then some choices can be subjective, but you will not regret it.

 

Regarding the blade:

The price is not that low, it does not make me scream at the deal of the year.
The blade is in Japan so as always I see no reason not to have it papered, so I would ask the seller for mediation by paying a deposit  fully refundable if the blade doesn't pass, if the blade pass I would pay the related certification costs + extra for the service (Obviously estimated beforehand) if the seller refuses I would pass.

 

Kind Regards

 

Giordy

 

Dear Giordy,

 

This was purchased from an auction by a friend of mine. Broker suggested its a good price, everything point to a good sword. Only problem he did mention to me was the paper, he did say “ It’s a good sword, everything is good beside the paper. If I want to resell for better value I better get it to shinsa. But for cost effective it wouldn’t increase much for all the work to get new paper for it. Sword has decent polish at the moment but I suggest you to send it to polisher before submitting for shinsa. “
 

So for me, I decided to keep it as my first sword. And I bought another Nobukuni with new NBTHK paper. So I can compare them side by side. 
 

Thank you Giordy.

[sabiji]

Hello Minh,
I think your urge to explore is very good. 

However, it's always better to research first and then buy. Unfortunately, the reverse is most common. Well, you seem to be a young beginner, and then you really want to own something, even if you get advice to the contrary. But I can completely understand you.

 

A homework assignment for you now could be to find out about the history and stylistic working methods of the various Nobukuni branches. What are the special characteristics of the (legendary) first two generations (there is still a lot of controversy and mystery here)? What are the special features of the Oei-Nobukuni? When did a change of style to Bizen-Den begin? When did Nobukuni swordsmiths move to Kyushu, especially to Buzen and Chikuzen, and why? Did this have an impact on the way they worked, and if so, what was it? Are there any differences between Buzen and Chikuzen? What possible connections and interactions are there with the immediate neighbors in Bungo-Takada?
When and why did the Buzen Nobukuni disband? Did the remaining representatives possibly move to Chikuzen or Bungo? Why did the Chikuzen Nobukuni survive until the end of the Edo period?

Isn't that a project?

 

Look at so many Nobukuni blades of various branches with your own eyes. Collect information, photos, Oshigata, and learn to draw Oshigata yourself.

 

And in 2, 3 or even 10 years, you may be able to provide us with valuable information. You will help others here who are not familiar with the Buzen-Nobukuni to see unknown schools in a different light.

That's how it works, and no other way, if you take a serious look at the subject. Let's go!