A thin piece of metal attached to the heel side of the outer part of tabi socks, hooked onto looped threads attached to the cloth of the inner part of the socks. Tabi socks were fastened to the feet with laces until the early Edo period, but kohaze started to be used around the mid-Edo period. There are four-piece, five-piece, and other types depending on the region and preference. In the case of Noh plays, four-piece kohaze are often chosen because they allow more freedom of movement at the ankles during long sitting times. The kohaze is marked with the manufacturers’ name and size, and the name of the customer is sometimes added to custom-made tabi socks.