The Japanese belt is known as an OBI, which is a three-letter word. The OBI is a wide sash worn around the waist over a kimono, a traditional Japanese garment. It is usually made of silk and is tied in the back with a large decorative knot. The OBI can be used to hold the kimono in place and also to add a decorative element to the outfit. The OBI is an important part of traditional Japanese dress and is often seen in modern fashion as well.