The Japanese turned out some great binoculars during WWII and after. I have two which were made around 1960. A 7X50 which was made for the Australian Navy and a 6X30 with identical construction. The larger one has a range finding gradicle.
The 6X30 only has Nippon Kogaku (Nikon) while the 7X50 has Nikon and Nippon Kogaku. They both have individual eyepiece adjustment which I suppose makes it easier to make them waterproof. There is a fair amount of wear on the outside of both but the glass is perfect and not a hint of dust or haze in either.
The quality is breathtaking. Not as good as the Nikon edg or the best Zeiss or Swarovski but still way ahead of all but the very best even now.
I also have a 7X50 marked “made in occupied Japan” These are also just marked Nippon Kogaku. Nearly as good as the other two and way ahead of the typical discount house binoculars.
Binos for stargazing are awesome. Binoviewers for telescopes are awesome squared.