I've recently watched the 47 Ronin (2013) movie, and some flags that appeared on movie attracted my attention. Don't worry, no spoilers!
One of the patterns that appear more often on the movie is, as I was found on my research, the mon of the Asano clan. Asano Naganori was the daimyo of the samurais that would, during the movie, became the forty-seven ronin (masterless samurai) of the title; it was usual to commoners without mon to use those of their patrons or organization. That mon consists of falcon feathers in saltire; falcon feathers were a popular pattern for being used in arrows, and in decoration for some special occasion.
Many flags with this mon appear on the movie, for example on this scene (don't know about historical accuracy). Here's one of those flags I reconstructed:
Japanese mons are used even today as symbol of a family, organization or clan (similarly to Western coats of arms and badges), and are very simple and monochromatic. They commonly appear in architecture, personal marks and, on the age of the samurai, flags, specially during the battles.
The mon were excellent during samurai battles, as their simple designs could be easily used to distinguish friends and foes. As explained on a previous post, the Japanese mon is the base of the Japanese flags tradition.
Comments are welcome.