its a dutch klewang rebuild by the Japanese
my Englisch is not so good so i copy some text from the internet
This 'sword' of yours is a modified Milsco Klewang/Cutlass. A little history lesson:
These Milsco Klewangs where produced bij the Milwaukee Saddlery Company, Wisconsin USA for the Dutch colonial army in the early 1940's. Based on the orginal Dutch Design.
The klewang was designed to give the Dutch soldier a good weapon against the edged weapons used by the resistant in the Dutch colonies.
After the Dutch got overrun by the German army in may 1940, the exisiting order placed at the in the Netherlands located Hembrug factory could not be delivered. So the Dutch Colonial army had to find an alternative, wich they found in the USA.
Unfortunately the war also reached the Dutch Indies about a year later, at that time only a small amount of Milsco produced "Klewangs" where issued to the troops.
A small part of the remaining stock was issued (not officialy) to the US Navy. After the war the Dutch War Departmant bought the remaining stock and issued them to his colonial troops and navy. The klewang was used in Dutch service till 1949.
After the Japanese victory the re-issued the captured klewangs to their own troops after some modifications. This so called "Heiho" klewangs had their handguard and blade altered. Exactly as your piece.
Jan.k