"布団" (futon) is a traditional Japanese bedding system that consists of a mattress and a duvet. Typically, the mattress is placed directly on the floor, providing a firm sleeping surface. The duvet, known as "掛け布団" (kakebuton), is used for warmth and comfort. Futons are lightweight and can be easily folded and stored away during the day, making them a practical choice for small living spaces. Futons are often made from natural materials like cotton or wool, allowing for breathability and comfort. In Japan, it is common to air out futons in the sun to keep them fresh and free from moisture. This practice contributes to the longevity of the bedding and promotes a healthy sleeping environment.