 SYNC: When Algren and Katsumoto are shown in slow motion, during the  horseback charge, Algren draws his sword and we hear the sound of  the sword ringing as it is drawn. The Saya (scabbard) of the Katana  is typically made of wood, and though they sometimes had fittings  made of metal around the Koiguchi (mouth of the scabbard) these were  usually ornate, and there clearly are none on the sword that Algren  has.