Rivkin

Polish is a bit heavy on hadori, but generally the first class Hizen hada is very repeatable, tight with itame's nie being like a dot or protruding a bit along the blade... This one is rougher, wider, more spaced, and non-uniform. Its still nice, but not to the same point. Weaker Hizen smith is an option, but so is a better than average shinto smiths who was inspired probably by Hizen Masahiro.

I suspect it might be not Hizen.

Irrelevant.

A lot of circa 1510-1540 provincial (and not only) work is not very distinguishable. There are even Bizen blades that look like Mino and Mino which look like Bizen. This one leands more towards Mino, but it does not tell you much. Its one of the many period's blades, maybe a bit later (1570) judging by sugata, though its not certain with such pictures. There are also plenty of unrecorded smiths, and some of them did use more famous Rai or Bizen names, so you do see ... mitsu on blades from basically everywhere.

I feel its another case when Japanese introduce a noun to mark something specific, but westerners would just see it as one element within many similar ones. Its very hard to judge Hizen away from Osaka based on hada alone. If its a specific smith like Hizen Tadayoshi the third generation, maybe you can, but if you mix seven Hizen blades from different smiths with seven Osaka I would be very hard pressed to tell which is which based on hada alone. Yes, every dealer will write "and you can definitely feel its konuka hada!" when selling Hizen. You can judge Hizen versus Bungo on hada though.

Very tired or more likely tired and poor polish.

It looks like a nice blade. Naoe Shizu has a "bad" reputation because it can be Muromachi, but its one of exceptions where mumei blades can definitely get TH and go Juyo, so its kind of judged by Nanbokucho principles, same as Oei Hasebe and a few other schools. I think sue-Sa is another possible attribution here, hamon is a bit more nie heavy on top, which is often seen in west Japan's schools like Sa or Naotsuna, while Naoe Shizu tends to be more harsh, larger nie throughout the entire hamon, also with more prominent masame. But one sees it in Naoe Shizu now and then as well and overall the attribution appears solid. On the negative hamon here comes out a bit soft since it lacks prominent sunagashi etc. Jigane is good. If it would have stronger nie in hamon definitely Juyo grade, though such statements are very subjective. As is, can still be an attractive blade. Feels like the earliest Muromachi.

Either about 2-4 days or until they steal it.

1. It will not pass Juyo. 2. Its a Nambokucho blade with bo utsuri, weak mostly nioi hamon and lots of masame with a bit of hotsure. Why it was appraised Aoe remains a bit of mystery since there is no ko choji, no dan utsuri, no chirimen, no fine tight itame. Boshi is consistent with Aoe. I guess the suggestion is that the only reason it passed as Aoe is because of kinzogan (kimpun? can't see). If you remove it, submit to TH it will be Mihara... and will cost 50% as much.

Apologies for honesty - this is average. Its genuine in a sense of school, but its late and rather run of the mill piece.

This is usually followed by a purchase of end Kamakura Senjuin or Naminohira with a long discussion on how the experts in Japan affirmed its to be Heian... Or if funds are present, than its Ko Hoki. Reality is, if you are not buying Sanjo Munechika there is very little difference between the earliest Kamakura and Heian. One has to accept the uncertainty.

I like it. Houju?

1) Yes, generally the blades which "had no historical value", especially yari and naginata had to be surrendered for smelting. Long blades were not targeted as much since they were seen as potentially important; one could donate them to be mounted as officer swords or held in reserves. There were volunteer groups which could appraise the blades and decide what could potentially be done with them, but generally they did not bother with yari which were by default considered "peasant stock" and smelted. 2. There is a connection between naginata and women in Japanese tradition and also between naginata and sohei, but actual historical documents tend to be sceptical on both. Female bushi were not too uncommon until the Mongol invasion, during which it was realized they generally just held the land rights while sending male relatives to fight in their stand, so the practice of female bushi head of the clan was severely restricted afterwards. There was still a notion of a female bushi being the last defender, for which purpose they did practice with naginata but such hard distinction as seen today in Japanese schools, i.e. females practice with naginata instead of katana, did not exist. Woman could practice with a sword and not all women had naginata skills.

It looks like lower grade shinshinto in mino style.

There is a guy there who takes shinshinto blades, uses some interesting chemical to make very dark utsuri and sometimes he puts a signature with a gold marker or chisels ichi if he passes it as ichimonji. P.S. No, you are not going to buy a quality blade for 50$ that others missed. You'll save yourself and us a lot of time if you stop trying. Yes, we all made our share of mistakes, and many were worse than this one or certainly more expensive.

Tosa Yoshimitsu was a very long lineage with many Muromachi generations, the first one was probably the very end of Kamakura though. Its hard to judge but the blade does seem to have strong masame, and Yoshimitsu's work do tend towards strong masame. Thickness of kasane (back ridge) is a strong kantei point for Yoshimitsu and can also help with understanding which generation it is. So far everything looks good.

The curvature change in nakago is not pronounced, I think its a different class of shapes.

I think its classic Echizen seki. An attractive one, with good jigane (almost makes me think shitahara as an alternative), good though not very strong on nie hamon. The issue with shinto sorry to say but there is not much to research. In koto its like crazy world with attributions, in shinto there is just not much to say.

.... and the forum turned into 10 messages a day asking - hey, I have this 50$ sword I want to buy, tell me about it. Not gonna provide the link though, cause don't wanna you scooping my treasure. 100x100 pixels pics will suffice.

Masahiro generally did not make periodic gunome, its more Mino/Jumyo kind of thing.

It gets difficult to comment since there is a competing interest, but frankly it just does not look exciting as a blade. Nakago can be tolerated in something old, this is likely early Muromachi, but overall there is just not much.

I can't contain myself... The thing is that there is Nobuhide horimono's kantei feature connected to how his hamon became at some point softer than the rest of the school. The funny thing is whether its seen or not here is debatable.

This seller specialized in Problematic blades with many kizu. You can get a good one, but you have to know what to look for. Its can be shinshinto/meiji blade and not really much of a collectible in all likeness.

In theory they can put school (province), period, even generation in papers. Often there will be hints allowing to pinpoint such data, even if its not stated directly... sometimes its what missing that counts, like the Masamune will simply go by his name, but something like "Shitahara Masamune" will include school's name. Its rather cryptic and requires significant experience to understand. With a rather basic signed blade 90% chance they will copy the signature as they see it, ... in places they can't read, and say its authentic. Is it worth it is a question to someone willing to spend... I would just use the same money and buy a second blade.

Its basically the same school.. 950,000 is sort of ok retail wise, for me its a bit high, but this is the territory where a conflict of interests appears - we are all collectors and we all sell stuff, so we might be unfair to other offers.