WW2 Japanese Flag

Was wondering if anyone has any info on a flag that I have that was taken from japan in ww2 Pic is just a poor drawing done on paint but if anyone thinks they could help me with what the flag is i can get further real pics of it

 

Do you think the background colour was originally red? - if so it could possibly be related to the japanese imperial family flag, although I found none with the bird - I'll keep looking.

 

The flag is in pretty good condition it may have been originally red but I feel that it is orange but close to red My drawing may not be exact. The flag was retrieved from Hiroshima. Ill get some pics the next time I look at it.

 

I found nothing else close so far - will try again later. Actual photo might help.

 

Here is a pic of it in its case

 

Sorry I've got nothing. Best I can even suggest is that it has some very very vague similarities with some items from both Tibet and Mongolia, but I'm afraid I can't find any references to confirm that past a vague impression.

Hopefully someone else will have a go at finding it, I've drawn a complete blank