A fan used to cool or for ceremonial purposes. Generally the same as sensu 扇子, although ōgi generally refers to a larger type of folding fan. The fan tradition was introduced to Japan in the early 6th century from China through Korea, where flat, stiff fans *uchiwa 団扇, were employed. Folding fans were invented by the Japanese in the 7th century. These fans, hi-ōgi 桧扇, were commonly made of 20 to 30 thin, flat pieces of cypress wood fastened together. From the Heian period on, fans were traditionally carriedby both male and female courtiers. Another type of fan, kawahori 蝙蝠, was made of bamboo or wooden frames covered with paper or silk. This fan-name uses the characters for "bat" kōmori 蝙蝠 because when unfolded, the fans resemble the outspread wings of this creature. During the Kamakura and Muromachi periods, the warrior class carried fans when dressed in formal or court attire, and although the hi-ōgi was still employed by aristocrats on occasions of court ceremony, the kawahori became more universally popular. Fan decoration is an art unique to Japan. See *senmenga 扇面画. A variety of materials may be used--designs and paintings in both ink and colored pigments, calligraphy, mica, gold and silver leaf. Often the ribs of the fan are made of beautifully scented wood or are perfumed. Various games with fans developed during the Heian period, such as ōgi-eawase 扇絵合, fan competitions, and ōginagashi 扇流し, floating fans on water. Fans also accompany actors in traditional *Noh 能 theater performances, during the tea ceremony *chanoyu 茶湯, and are often exchanged as gifts.