It’s a box-shaped bed which is used in the regions with cold climates such as Fukushima and Nagano in the past. It’s a wooden box of about the size of a tatami-mat (35.8 × 71.7 inches) and about 11.8 inch depth filled with straws, and bedding goods such as a rush sheet(mushiro) and shiki-buton are laid on it to sleep. This bed is said to prevent cold air from entering and keep the inside warm during sleep.