The legend says that Susanoo-no-Mikoto, kami (god) of sea and storms, as thanks for the hospitality, thought a man how to get rid of an epidemic that broke out in his village, by tying around the waist a ring of woven grass. That's how the Chinowa ritual got started, and today it signifies purification and clearing of bad luck.
Usually, a large ring made of chigaya cogon grass is placed in front of the shrine, and the worshipers are passing through it, but the grass is not really important: inside the Kumamoto-jo Inari Shrine, next to the Kumamoto Castle, I found this modern Chinowa ring...
EXIF info:
Nikon Df
Lens: 24-70mm F/2.8G
Focal Length: 26mm
Aperture: F/5.6
Shutter Speed: 1/500s
ISO Sensitivity: ISO 640