The koto is a plucked string instrument from Japan. It has thirteen strings made of waxed silk, or sometimes plastic, which can be tuned by movable bridges along the width of the instrument. A descendent of the Chinese instrument the zheng, it was introduced to Japan from China in the 7th and 8th century. Kotos are about 180cm in length, 8cm high, and 23cm wide and normally lie flat on the floor while being played. The koto is played sitting on the floor, the strings plucked by the right hand using plectra on the thumb and first two fingers while the left hand modifies the pitch of the the strings by moving the bridges which sit under the strings. The koto has been regarded as Japan’s national instrument since the 17th century.