Kokyu Kokyu is mostly provided with three strings (although some have four strings), and its shape is roughly a smaller version of the Shamisen - a three-stringed Japanese banjo. Almost the same materials for Shamisen are used; nowadays, for the neck part, koki (literally, red wood) or Shitan (rosewood) is used or quince (Fabaceae) for popular versions, and for the main body, Chinese quince is used, with leather of cat or dog and silk strings utilized as well.

In a broad sense, the term 'kokyu' is sometimes used for collectively calling stringed instruments. In the early Meiji period, even violins were called Kokyu. Generally, it is sometimes used for indicating all the stringed instruments in Asia, but the definition is not clear. Therefore, even Chinese stringed instruments erhu (two-stringed Chinese instrument played with a bow) and gaohu (Chinese bowed string instrument developed from the erhu) are sometimes commonly called Kokyu.