I AM LOOKING TO SELL A WORLD WAR II JAPANESE SWORD ... THIS IS WHAT I HAVE FOULD OUT ABOUT IT ...
The translation is mostly correct, however, it was not made at the Okayama prison. That swordsmith, the warden, was named Emura, and he did sign Nagamitsu on some of them, but this is a different Nagamitsu. Yours is Ichiryushi, that was his art name, and he was commissioned by the army to make swords for the Osaka Arsenal.

Yours is Ichiryushi-Nagamitsu that was his art name,

The Hawley number for your sword's smith is NAG-296. The Okayama warden is EMU-1. Yours is in Slough's, page 124. (An Oshigata Book of Modern Japaneseicon Swordsmiths 1868-1945)

This is a very good sword. Medium to High Grade Gendaito. That means 100% traditionally made, traditional ore and water tempered. And according to Slough's, these swords' cutting ability ranks among the best produced by showa period swordsmiths. .

What you have there is a late war officers pattern, commonly but erroneously referred to, even by collectors, as a "Naval Landing Forces" sword. It is the real deal, maybe oil tempered instead of water, just missing some parts, and the wrap. Looks like a nice enough blade, too, worth some effort and money to get it restored.
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