PNSSHOGUN

Certainly a candidate, especially with all of the Count Ito documents and tags remaining. Perhaps just submitting the Koshirae for papers would be a nice addition to the provenance.

Some authentic Onshi Habaki. He was noted as a recipient of an Imperial Gift sword when graduating from the Army War College in 1916. That was well before the introduction of the Shin Gunto, and Shibata Ka's working period as a Tosho. The other thorn in this is the fact Yamashita was well out of favour with the Emperor due to his association with the Imperial Way faction and the February 16th Incident.

Portrait of Tojo Hideki with his special Gunto, this is the same sword now in the MacArthur Museum.

Not sure what to make of this sword, made by Shibata Ka with Yamashita's name inscribed on the Omote. It has the Kanji for 御賜 Onshi - Imperial gift, yet Shibata Ka hasn't been known to make such swords before and generally these were limited to the Yasukuni Shrine smiths, the Horii Mon, and the Gassan Mon. https://thebestantique.com/zh/product/general山下奉文-98type-sword/

Sword No.166 in Han Bing Siong's "Japanese Swords in Dutch collections" is noted as being found in military mounts before being polished and achieving Juyo Token:

Great read, it would be nice to have more examples of their works and scans of the original documents sprinkled throughout.

That is a very good addition, congratulations. Rather fortunate that the original Koshirae and inventory tags remain, and heartening to see other pieces have been kept together after all these years.

The Hideyoshi Koshirae also appear in Paul Martin's book:

Yoshinobu is more of a first name, sometimes with these tags there is both Kanji and English text to confirm a name.

Hello Niels, welcome to the forum. Your friend has a naval officers sword, or Kai Gunto, which looks to be in decent shape. Value will depend on the quality of the blade, which we will need more photos of to determine. There's a instructional guide on how to safely remove the handle to check the maker:

These are often fairly crude and can vary from having real old blades to oil tempered pieces, it would be interesting to see if you can get the nut off for a picture of the tang. For $5 it's a neat bit of history.

Perhaps a variant of Katabami? https://irohakamon.com/kamon/katabami/mitsuwarikatabami.html

The Showa smith Kanenaga was known for making Tanto with similar extensive script Horimono.

Unfortunately what you appear to have is a relatively recent sword (late 19th century to early 20th century) where fairly poor pieces (by Japanese standards) were made for export to foreigners. They often feature elaborate (but simple) Koshirae that would appeal to the foreign buyers with little knowledge who bought up all sorts of Samurai wares to decorate rooms or whatnot.

What a curious example, usually these are much smaller and simpler. It may be a presentation/dedication inscription too.