The "koto" has existed in Japan since ancient times, and documents show it was used as an instrument for magical rituals. It is thought to have existed as an instrument since the Yayoi period (10th century BC onwards), and later, when many stringed instruments were introduced from the continent, the term 'koto' became a general term for string instruments. There are a variety of materials, sizes, and playing techniques, but the basic principle is that it is a traditional instrument that produces sound by plucking strings.