SteveM

On page 274 of Wakayama's 刀装金工事典 there is a 春秋 (my guess is the pronunciation is Haruaki). Says he is a student of Yanagawa Naoharu, was allowed the use of the Yanagawa name, and that he sometimes signed 柳川春秋.

Yes - Hidetoshi is the smith, and Showa 17 (1942) is the date of manufacture. With these WW2 blades you have to understand that the smith may not have actually hand-forged the sword. He may have just overseen the machine production of it. I think the presence of the Seki arsenal stamp virtually guarantees this one is a mass-produced sword. Still, it is an interesting artifact and I would refrain from scratching it up with a piece of steel wool. There are a lot of threads here that discuss the dos and donts of blade cleaning. Search a few threads to see what the guys here say.

丸に篠笹　or 丸に根笹 Maru ni shinozasa Maru ni ne sasa #05 on the list below http://homepage3.nifty.com/omaturinotakahasi/kamon.sasa37.htm

Found this one on the web, if it helps. http://www.e-sword.jp/katana/1510-1085.htm

Yes, this last round totally stumped me. This piece, the ura-mei of the signature on the WWI sword in the other thread, and the art name on the tsuba. Morita-san hit all three out of the park. That ura-mei particularly stumped me. I couldn't pick out anything but the final 作

秀俊　Hidetoshi Reverse side says 昭和十七年　Shōwa 17 Seki arsenal stamp on the tang. Ignore the painted on numbers. They say "1726", but they are of no importance to determining the sword's value. You ought to get those fingerprints off the sword asap. Hopefully they are not rusted on to the blade.

国英 Kunihide Kuniteru is another possible reading, but I saw Kunihide on Jinsoo Kim's site (for WWII blades) so I think this is probably Kunihide. Enjoy as is. Polish it only if you have money to burn.

算経 Sankei

I think those couple of characters in that line are 小反 (kozori). Also, the 伝 (den) at the front is worth mentioning.

No, I think John's was the right answer. 越州住兼植 Esshū jū Kanetane. A few smiths used that name.

The steel looks almost featureless, except for the white hamon, which in the very top pictures looks like the edge ends in a foamy, bright white line. In the second group of photos the white line isn't to be seen, so maybe its a trick of the lighting used for photography, but the second group reveals the hamon to be free from any activity. It is just a bright area, a consistently pale wavy strip, on the steel. So the clues point to a WWII-era Seki blade with no characteristics of hand-forged steel, and that is why I assume its a mass-produced oil-quenched sword. Looking at it positively, I would say its a nice piece for collectors of militaria.

Actually, that 石井 looks to me like 研 (maybe 上研 uwamigaki?)

Family crest is called 菱に二つ引き　(hishi ni futatsu biki), meaning just as you would assume: two lines in a diamond shape. Related crests, such as two bars in a circle, are associated with the Ashikaga family, so this could be an offshoot from that family. Bear in mind that the association has become diluted with the passage of time. https://ja.wikipedia.org/wiki/%E5%BC%95%E4%B8%A1%E7%B4%8B

Well, now that would really piss me off! I think probably your assumption is correct. I would definitely ask about that. But what a disappointment - after going through the trouble to translate something, then having it get buggered up in the final step. I'm feeling your pain, Piers!

The odd English is a pet peeve of mine. In short, my guess is that the curators were cutting costs on the exhibition, and opted for someone who may have relied heavily on machine translation, and/or skipped proofreading.

The one on the bottom is 南　(Minami, or more likely the on'yomi of ~nan when combined with the kanji on top). The top one, however, is a mystery to me.

The reverse side is: 慶應二丙寅仲秋 Mid-Autumn, Keiō 2 (1866)

Morita-san has already done the hard work for us. Take a look at this post from earlier last year from the same smith, and an identical inscription. http://www.militaria.co.za/nmb/topic/17291-mei-probablement-showa-me-ch/

I think the writing indicates the sword was presented from the Governor-General (not a present to the Governor-General). The recipient is unnamed.

I agree with Jean above regarding the blade. Perhaps it was created in a Seki foundry. Seki is an important sword-making region in Japan, and there was a foundry there making swords for the army under the supervision of some smiths who then sometimes put their names to their swords. Kanehisa was from Gifu-prefecture, which is where Seki is located. So if I had to judge from your photos (which is often a dodgy proposition) I would say yours is an oil-quenched Seki blade. This doesn't mean it is trash, by any means. It has value as an historical artifact, and there are a lot of collectors of Japanese WWII swords no matter what quality of steel or how it was forged. Unfortunately for you, your sword furnishings (scabbard, tassel, menuki, etc..) look like they've all had a rough life. I think it will probably be too much effort to try to restore the sword and the furnishings to museum quality. And because there were so many of these items produced, it means there are still a great number of high quality pieces intact, or reconstituted from surplus parts, which makes restoring or replacing damaged pieces a labor of love that will cost more than the end product will be worth on the open market. I think you should take care that any rust doesn't spread, and read up on this site how to store the sword, and you should have a very interesting keepsake

The first four kanji are the name of a pro-wrestler turned politician (and back to pro-wrestler) here in Japan. 大仁田厚　Ōnita Atsushi https://en.wikipedia.org/wiki/Atsushi_Onita Maybe he also moonlighted as a swordsmith??

The sayagaki says 賞　朝鮮総督　南次郎 Present/Award Governor General of Korea, Jirō Minami https://en.wikipedia.org/wiki/Jir%C5%8D_Minami

I chose Onoki because of the Onoki that appears in the list of RJT smiths (the same smith one that John Stuart mentions). I think probably there is some connection with Naoji, considering the same 治 kanji is used in both of their given names.

小野木米治 Onoki Yoneharu (?)

I think this is a different sword from the one Tsuruta-san bought 30 years ago. The sword up for auction is a consignment sale. (And, 27m is the starting price...no telling where it will end up.) But, having said that...50M is a huge amount. Would like to see that sword. Wonder where it is. Wish I had a cool 50M to go spend sword-shopping at Southeby's.