Kohaze means "connecting and uniting things with a hard material." Kohaze are fingernail-shaped clasps for fastening the closure of traditional Japanese socks, leggings, hand and wrist covers ( tabi, kyahan, tekkou ). They are attached to the closure and hooked onto "kohazekake" ( a hook on tabi). Kohaze is famous as "easy to fasten and hard to come off". So it is used for the excellent Tabi worn by Nou and Kabuki actors engaged in Japanese traditional arts.

Tabi, the traditional Japanese socks, were invented in the middle of the Heian era ( 794 - 1192 ) to prevent the slippage of the clog thong. But tabi were not generally worn because common people could not wear them without the permission of their feudal lord.

It was not until the middle of the Meiji era ( 1868 -1912) that Kohaze came to be used to fasten tabi. During the economic boom after World War I, even 18 karat gold Kohaze appeared on the market.

When World War II began, zinc - coated and iron Kohaze were produced as a substitute for those made of brass. However, they easily rusted and stained the tabi, leading the government to distribute aluminum for making Kohaze.

Although plastic Kohaze were also produced, they were not practical. As a result, the number of Kohaze per pair of tabi was reduced from twelve to eight.