Tatami mats are a quintessentially Japanese flooring material. They're made of rice straw, covered in woven soft rush. This gives them just the right amount of give, and a fresh natural fragrance. Tatami rooms are used for eating, sleeping and relaxing. They're also important for the tea ceremony and martial arts. Our guest is Koshima Yusuke, one of Japan's leading young architects. He talks about the positive qualities of tatami, and discusses potential new uses in the modern era.