You've probably seen this kind of post before...my grandfather returned from WWII service in the Pacific Theater with many souvenirs, including this sword. I believe that it may have been purchased in Hawaii.
The intricacies of Japanese sword identification seem somewhat daunting, to say the least. I would like to know if this sword is "real" or a knockoff sold to American GIs. Any further information you can provide would be helpful. I'm not interested in selling the sword, just curious as to what it actually is.
The Reddit translator section tells me that the inscription on the tang reads "Bishu Osafune Yasumitsu" and that the paperwork accompanying it is a samurai sword certificate. I have not had the inscription on the edge of the hilt translated; any translation help is appreciated.
Images are at https://neotokyo2040.imgur.com/all/ (image of certificate is also uploaded)
I can certainly add more photos if this helps; just let me know what images you need.
Thank you in advance,
C. Nelson
