Washitsu (Japanese-style room)
A washitsu is a room with tatami flooring as opposed to the wooden or tiled floors of the rest of the house. Tatami mats are made of a thick base of packed straw (toko) covered with smooth mat made of finely woven rush (igusa). Tatami sizes are standardized and the term jo, used as a counter for tatami mats, is still used today to indicate room size, even if the room is Western style. While there are some differences by region, in the Tokyo area the typical tatami mat usually measures 1.76 by 0.88 meters (5.8 by 2.9 ft.) with an average thickness of 6 centimeters (2.4 in.)
The window and door fixtures of washitsu are sliding partitions called shoji and fusuma. Fusuma are sliding partitions covered on both sides with cloth or paper. Formerly called fusuma shoji, today the term shoji refers only to sliding panels consisting of a wooden frame with translucent paper (shojigami) applied on one side. Since shoji admit light, they are also installed in window frames and used for decoration. As home interiors are increasingly built in Western style, shoji are becoming less common.
Another common feature of the tatami room is a tokonoma, or decorative alcove. The tokonoma adds an element of formality and ornamentation to an otherwise unadorned interior. The main features of the tokonoma include a decorative corner post (tokobashira) - floor frame (tokogamachi) -- tatami or wooden flooring, usually raised a few inches higher than the rest of the room -- and the upper-frame beam (otoshigake). A scroll or other picture may be hung on the back wall, and a flower arrangement or art object displayed on its floor.