The first folding fans were quite similar to the ones we use today, made of wooden strips connected with a metallic rivet and tied together with silk strings. Later, the Japanese craftsmen started using washi (Japanese paper) on a bamboo frame.
Used in Japan by both men and women, sensu is not only for cooling - it is also a fashionable accessory, a symbols of status or a ceremonial item. You will see it used in traditional dances, by Noh or Kabuki actors and even by Shinto priests.
The samurai warriors were also using folding fans with metallic outer ribs (gunsen or tessen) as unsuspecting weapons.
Today, the Japanese folding fans are some of the most popular souvenirs, being available in a huge variety of models and designs, as you can see in this specialized store from Higashiyama, Kyoto...
EXIF info:
Nikon D90
Lens: 8-16mm F/4.5-5.6G
Focal Length: 8mm
Aperture: F/5.6
Shutter Speed: 1/160s
ISO Sensitivity: ISO 200