Ray Singer

Bruce, the kikumon + Ichi kanji (kikuichi) is a reference to the Kiku Gyo-saku produced by Emperor Gotoba. You see this as a tribute appearing in later swords, such as several Yokoyama smiths, Shimada Sukemune and others. https://markussesko.com/2013/03/04/about-the-goban-kaji/

This is the second generation of the Shinto Yokoyama Sukesada lineage, circa Genroku (1688). It appears to be suriage.

(Kikumon Ichi) Kawachi (no) kami Sukesada Bizen (no) kuni Osafune ju

The mei is incomplete due to the suriage nakago. Bushu Shitahara ju ___. No smith name present.

Unfortunately I am away from the koshirae for a few weeks, but the photos on my laptop were just good enough to enhance and show how the ashi is bisected lengthwise (they pull apart as two ashi along the seam).

Perhaps Mike Quigley. https://www.google.com/search?q=Mike+quigley+site%3Awww.militaria.co.za&client=ms-android-google&hs=1mBB&sca_esv=0237a3a71ba987c6&sxsrf=APpeQnvBsQ8VIWBQ7rLDp0Wp7TXMjEqIOA%3A1787834335409&ei=3y-QaubTGOCxur8PhdOzyQI&biw=411&bih=753&oq=Mike+quigley+site%3Awww.militaria.co.za&gs_lp=EhNtb2JpbGUtZ3dzLXdpei1zZXJwIiVNaWtlIHF1aWdsZXkgc2l0ZTp3d3cubWlsaXRhcmlhLmNvLnphSJUcUPwNWOUZcAB4AJABAJgBP6ABwwOqAQE4uAEDyAEA-AEBmAIAoAIAmAMAiAYBkgcAoAdgsgcAuAcAwgcAyAcAgAgB&sclient=mobile-gws-wiz-serp

There are two loops. There are side by side lengthwise and overlapping, so that you see only one in profile however when this comes apart they separate into two individual, functional ashi.

It always impresses me to see the workmanship involved in one of these. I've seen several such ashi, and they are always for very high quality blades. This example below is a juyo Enju in my collection. https://nihonart.com/portfolio/juyo-enju-tachi/

I'm sorry to ask this but how certain are you that your friend acquired this in Japan? Based in the photos you provided, it is clear that this is not a Japanese sword. It is a type of commonly seen fake. This type of item could not have been in Japan, as you are not legally allowed to own or license swords in Japan if they are not traditionally made (nihonto). The article below will help identify these types of pieces in the future. https://www.jssus.org/nkp/fake_japanese_swords.html Best regards, Ray

As far as the blade being unsigned, that is not unusual and it appears the blade is a oil quenched showato arsenal blade (with togari-gunome hamon).

You have shown the date side more clearly here and in the correct orientation. The full date inscription is: an auspicious day in October, 1939. Best regards, Ray

The kanji and reading are below: 大和守国貞 - Yamato (no) kami Kunisada.

Please absolutely do not do anything on your own to clean the blade or remove rust.

Very nice find, this is a sword by the Yasukuni shrine smith Yasunobu. The blade is dated 1939 (Showa 14). https://www.google.com/search?q=Yasukuni+Yasunobu+site%3Awww.militaria.co.za&oq=Yasukuni+Yasunobu+site%3Awww.militaria.co.za+&gs_lcrp=EgZjaHJvbWUyBggAEEUYOdIBCTEwNDExajBqNKgCAbACAQ&client=ms-android-google&sourceid=chrome-mobile&source=chrome.ob&ie=UTF-8

The mei is: Hizen (no) kuni Yoshitsugu (肥前国吉次). Per Markus Sesko's compendium, there were two smiths who signed this way: YOSHITSUGU (吉次), Kan´ei (寛永, 1624-1644) YOSHITSUGU (吉次), Keiō (慶応, 1865-1868)