I posted in /r/knives and /r/swords but haven't had a lot of luck yet. Someone suggested trying here. All i know is its a Wakizashi. My grandfather got it in Japan at the end of WWII while in the army there. My own father has had it for many years. I saw a documentary talking about at the end of the war Japan had to surrender all their weapons. A lot were destroyed or presented to American soldiers. Seeing that reminded me of the sword. I tried to get a close up of the tang with the symbols on it. Any help or info about this is greatly appreciated. Thank you.
The grip and sheath are made for the storage of the blade rather than combat, hence the lack of guard. I'm not sure of the phrasing but such a grip and sheath are referred to as "Shirasaya" mountings, existing because prolonged exposure to combat grips and sheaths actually does harm to the metal of the blade.