Lit. sword rack stone. The trump stone *yaku-ishi 役石 set in front of the sword rack *katanakake 刀掛 at the entrance of a tea ceremony room *chashitsu 茶室. The stone allowed warriors to put their swords into the sword rack more easily. In the early Edo period the sword rack was hung about 160 cm above the ground and the height of the stone was more than 15 cm. However, when the sword rack was lowered in the mid 18th century, the height of the stone was also lowered. Because exceedingly low stones were considered unbecoming, visually compelling double-tiered stones nidan-ishi 二段石 were often used for the katanakake-ishi. The sword rack stone is usually placed at the side of the guest entrance to the chashitsu, but when there is a large space between the *fumi-ishi 踏石 and the entrance, one or two stepping stones *tobi-ishi 飛石 are used to connect the two.