It's super cozy and super fluffy. It consists of a mat, a thin but fluffy blanket that goes over the mat, a really thick and fluffy comforter-like blanket that goes on top, and an insanely taut pillow. I say the pillow is insanely taut because it's very high when you rest your head on it and it feels so tightly packed that it's almost hard. I'm getting used to the pillow. The bed, however, needs no getting used to. It is so comfy and warm and wonderful.
Also, in Korea, the rooms are heated through the floors, so a bed like this is a great way to stay warm. It's been face-blisteringly cold here lately, so it's a relief to have a cozy place to sleep at night.
