"yumi Japanese bow of composite construction, consisting of a length of hardwood and sandwiched between two pieces of bamboo, generally bound with rattan and sometimes lacquered. The yumi was normally about 2 m/6.5 ft long and had the grip approximately one-third up from the bottom of the bow. It was used from the Heian period (794-1185).
"It was fired from horseback and this differential enabled the archer to pass the bow quickly over the horse's body as he stood up in the solid stirrups (abumi) to aim and fire."
* Bennett 1998 p306
"tachi Japanese slung sword, originating in the Heian period (794-1185) and used continuously for cavalry use and carried with the cutting edge facing down. Different styles of tachi were also worn at court and on ceremonial occasions."