More research is needed before I can properly explain what's happening here. I thought that these men with the banners were advertising various products, and they are. For example, the red/yellow/black/green banner in the bottom left of the picture is a well known brand of ochazuke, which is a seaweed/various other dried items packet of powdery stuff to sprinkle on rice. Next pour on hot water for some delicious soup. I'm serious! Anyway, the advertising part seems to be right, but Aogu says that these companies get paid to traipse their banners around the dohyo. Which seems opposite of what I would think. End of confusing non-explanation.
posted by jcm