My Dad has a Japanese unit flag like that. He was in the Philippines, but got it from a guy who found it in a bunker in Saipan. Not sure what he traded to get it.
Its on the wall of his Seabee lodge now.
Soft chuckle.
When I was a young jarhead I got a lesson in geopolitics from an old man - a street vendor selling flags in Pohang Korea.
I had a buddy back home that I promised a Japanese flag, and this flag vendor was the first opportunity.
When we first met the old man he was quite friendly. However when I asked him if he had any Japanese flags, he immediately went silent. After a few seconds he muttered "'f...' the Japanese, then he walked away from us...