eternal_newbie

Yup. Specifically, "southern barbarians" - people who sailed in from the south. https://www.mandarinmansion.com/glossary/nanban-tetsu-nanmanshi

Saiha I believe refers to re-hardening, i.e. a (properly hardened) hamon that was reintroduced, likely by a trained blacksmith, after the original was lost due to heat damage. From having looked at the blade in hand, I believe that this blade is not saiha but rather nioi-gire: it has been heated to the point where most of the hamon is simply gone (because the rest of the blade was heated up to become homogeneous with the hardened area within the hamon). Instead, a polisher has overlaid a hadori on the remnants of the hamon for what is sometimes euphemistically called "preserving the sword's dignity". Given the sword's repurposing as a blade for iai, I don't hold any ill will against whichever polisher did this; after all, the same thing is done on most iaito, albeit using cruder means. I looked at it under every lighting source I could get my hands on - incandescent, fluorescent, halogen, even natural sunlight - and all I could see under the hadori were small blobs of nie and nioi, almost like yubashiri, along where the hadori boundary has been "painted". The exception as mentioned before is a couple of inches of contiguous nioiguchi that remain near the end of the monouchi, and that runs off the edge of the kissaki instead of following the hadori along the fukura. I believe what the photographs are displaying is those underlying remnants, which admittedly were sufficient to fool me into believing the entire hamon was real when I first got the blade.

Apparently nanban was a bit of a blanket term for foreign steel, including steel traded from the Dutch, brought in by travelers from China and Korea, and recovered from shipwrecks (of both Western and Eastern origin).

It was examined by a professional togishi, who agreed with the assessment that the hadori is mostly cosmetic, with patches of nioi remaining here and there to give an idea of the rough dimensions of the original hamon. However for the most part there is no nioiguchi left, with the longest remaining segment being a few inches at the end of the monouchi that runs out of the kissaki. Based on the condition of the steel and hamon, the conclusion was that it likely suffered fire damage rather than being retempered.

Many smiths were quite proud of this, and would inscribe it alongside the mei ("made with nanban-tetsu") because imported steel was seen as higher quality than locally refined tamahagane!

Also consider that koto blades have a somewhat unknown past. Even for well-documented swords, we have no way of knowing exactly how many shocks, hits, bends etc. they took before reaching us in its current state. If an old koto blade breaks after two cuts and a brand new (at the time) shinshinto blade withstood ten, is it that the shinshinto blade had superior craftsmanship? Or did the koto blade finally succumb after taking tens, or even hundreds, of such shocks on the battlefield (and having material removed via polishing and/or horimono)? For that matter, what impact does suriage have on the structural integrity of a blade that used to be much larger? It's a well-known theory that many smiths in the Kamakura and Nanbokucho period were so concerned with structural integrity that they signed with shallow lines instead of deep chisel strokes to avoid creating stress points in the nakago. For all we know, this may be the reason why some blades were simply not signed at all despite being ubu - the customer demanded the maximum possible resilience, or the smith was determined to provide it because of the importance of the intended owner.

There's also the matter of scarcity. Who knows exactly how well a Masamune cuts compared to a Kotetsu? Not even a Shogun would waste a Masamune on the testing required to prove that; meanwhile Kotetsu was alive and well and producing blades regularly. All we have are anecdotes about such-and-such cutting through a lantern stand, or so-and-so chopping a helmet in half. Worth noting that a handful of old masters did have their blades tested; in particular Shizu Saburo Kaneuji was ranked as ryo-wazamono and later upgraded to o-wazamono, and the first-gen Bizen Kanemitsu was considered peerless in cutting ability, even outranking his saijo o-wazamono peers like Magoroku Kanemoto and Kotetsu. Who knows how some of those other Kamakura/Nanbokucho luminaries might have fared if their blades weren't generally regarded as too precious to put to the test? Then again, perhaps their blades being too precious to put to the test was all the proof of their ability that the Edo-period connoisseurs needed.

The usage is greatly inconsistent; many serious collectors use gendaito to describe any sword made in the post-Haitorei sword revival period, while using showato to denote non-traditionally made swords from World War 2! Furthermore, there is another term which muddies the water further: shinsakuto, meaning "newly-made sword" - where "new" generally means any time after the Showa period (so 1989-present).

@DocTheRoc this got me thinking about where I'd seen a sword with a large collection of nakago-ana, and today I finally remembered. Check out this long Ayanokoji blade that was featured at last year's Japan Art Fair in Utrecht:

Some of the samurai in the Sengoku period were remarkably cavalier about modifying treasure swords for practical use. I wince every time I see Oda Nobunaga mentioned in a nihonto text, because the next sentence is usually "had it shortened to its current length of [60-65] cm".

Although in many, or even most, cases it's fairly cut and dry, the difference between a Naoe Shizu and Yamato Shizu attribution can often come down to a personal opinion on whether a sword is "Yamato" enough. Are three togari "too Mino" to be Yamato Shizu? What about four? Or five? Is the masame-hada pronounced enough? Is the shinogi too high for Mino (assuming shinogi-zukuri)? All of those cutoffs are arbitrary and for blades that cut it very close both ways, every person you meet at a given nihonto convention can give you a different answer to the last person! In the end they both amount to the same thing - the work of a relatively close descendant (by blood or by teaching) of Shizu Kaneuji.

Very nice! The Enso is one of my favourite subjects for calligraphy.

That's a lovely little Taima blade with a classy koshirae to boot. I'd be sorely tempted if I had the funds for another purchase!

Funnily enough, that's also how I found the sword initially; I had been searching for an iaito online for my own practice, and because the story about the iaido sensei was in the seller's description, the listing showed up in my search results. The koshirae is very nice for a fatally flawed blade, albeit rather low-key, which lends some credence to this story (as does the blade being extremely thin and light due to having taken so many polishes - suitable indeed for an elderly practitioner). I was particularly fond of the tsuba, which has some subtle detailing reminiscent of Kagamishi school work. At any rate, I am pleased that both you and the previous owner were both upfront and well-informed about the blade's condition, and that it has found its way to someone who can appreciate it for what it is and the centuries of history behind it.

Not while I owned it, but as per the linked thread, the general consensus seems to be Yamato or Yamashiro, late Kamakura to Nanbokucho (1320 ~ 1390). Personally I lean towards Yamashiro because of the lack of masame and the relatively flat shinogi, which would make Rai or Enju the most likely candidates (and indeed these are the most common guesses from the people who've examined it or seen photos of it). Unfortunately the main kantei difference between Rai and high-level Enju is ko-maru vs. o-maru boshi, and we no longer have a boshi to examine here.

As for the history of the blade; when I bought it, it had previously been used by an elderly sensei as a practice blade for iaijutsu and was sold on eBay to me when he became wheelchair-bound and was no longer able to continue pursuing the martial arts (and I have no way of verifying even that story).

I am sorry to be the bearer of bad news, but this blade is one that I previously used to own. It was examined by a polisher, who determined that it has been damaged in a fire and most of the hamon is gone; what you're seeing is a cosmetic hadori applied by a polisher to hide it. I ended up refunding it and selling it to someone who understood the condition and was willing to accept it as such. I would contact the previous owner seeking a refund if it was sold to you as being without any fatal flaws; however since you noticed that the hamon does not continue into the kissaki it sounds like you knew what you were doing, and hopefully obtained it at a reasonable price. Previous discussion here: https://www.militaria.co.za/nmb/topic/22108-ji-nie-question

If I'm not mistaken, that Morisuke tachi in the bottom image is the same one that was listed on Fred Weissberg's site: https://nihonto.com/bizen-morisuke-備前守助/ A grand old soldier measuring in at 87.7cm (34.5in) with a bunch of battle scars.

The only Yoshimochis of note are Fukuoka Ichimonji so it doesn't need to be qualified here. If they thought the mei was legit but belonged to some other, less well-known Yoshimochi, then they would add a qualifier in brackets.

It's not even the beefiest blade on their site! https://www.toukentakarado.com/item-tk031-kazuyoshi

Agreed; their photographs and descriptions have been useful in my own research as well. Not quite the super-detailed resolution you can find on some of the online museums, but a good deal better than most, particularly when it comes to getting different angles and orientations of the blade. Even better, several of their pieces are also showcased on their Youtube channel: https://www.youtube.com/@touken-world/videos

I always get tripped up by kissaki definitions - some kissaki that seem barely longer than a chu-kissaki will be described as "classic Nanbokucho o-kissaki" while others with kissaki that almost look long enough to be naginata-naoshi will be described as "extended chu-kissaki".

There is a JuBi zaimei tachi by Yoshimochi in one of the Sano Museum sword appreciation guides which, if anything, is even more subdued than the one being discussed here. Almost Yamashiro in shape and hamon structure.

Yep. Some sites that deal with higher end items will list prices all the way up to 9,999,999 yen and "Please enquire" above that. Aoi-Art is, as far as I know, the only dealer website that will give a price for everything, even items in the hundreds of millions.

Yes, usually the original Japanese text will say something like "bold", "robust" or occasionally "heroic". It is a cultural/translation issue that a translator equates these things with masculinity. As for "noble" - in this case, "noble" is quite literal; the tapering koshi-zori sugata with fumbari and ko-kissaki that you see in Heian and early Kamakura period blades were associated with the nobles at court, rather than footsoldiers on the battlefield.