Are the sheets under the quilts in Japanese hotels covered or covered?

It's paved There is a thin sheet under the quilt in a Japanese hotel. This kind of sheet is called "Flatsheet" or "Flatsheet" and is used together with "Fittedsheet" (that is, bed cap). There are tightening belts under the bed cap, which can be better fixed on the mattress. Instead of tightening belts, the "flat sheets" are spread on the bed cap to isolate and protect the quilt.