Not an expert by any means but that was my first thought as well... I posted the one above on the right, which was also confirmed as a "seabee special". Will be interesting to hear what others have to say---
Knowing the size might help. Seebee flags tend to measure in 20" to 26" range while on Japanese personal flags the short side is often in the 28" range and the long side up to 38" or 40". Not hard and fast but one general indicator.
This one looks like it was folded while the paint was still wet. It appears period, most probably a seebee special. The construction, painted sun aside, is nicer than usual... tie strings, reinforced corners.
Thank you for your answers! The seller asks $180 for it.
I have mixed feelings about it. Why would a GI write the exact time on it when he killed the soldier, but otherwise, someone who fakes a flag would write the capture infos on it but not the time?
That's way too high for what it is --- I wouldn't speculate too much about the inscription (why this and that), there's a lot better out there for that kind of money either way... this one's most probably a Seabee creation to boot.