This is a very rare rising sun flag from Taisho period(1912-1925) or early Showa period(Showa:1926-1989).
During WWII, people made and presented them to the soldiers with praying 'Buun-chokyu'(fortune of war). Many people wrote their name with praying the safe and victory of each solider.
Textile is cotton.
It has some flaws as photos show, but as a whole it is in very good condition.
photo:suh