It’s a summer kake-buton. There are several type of summer kake-butons: toweling blanket type, quilted blanket type, hada-buton type and cotton blanket type. Any of them has no fillings and even if it is filled with batting, the amount of the batting is very limited. The outer or lining fabrics, which won’t be sticky with sweat and feel smooth to the touch, are often used for the summer kake-buton.