The ancestor of the was the Chinese . It was first introduced to Japan from China in the 7th and 8th century. The first known version had five strings, which eventually increased to seven strings. The Japanese belongs to the Asian zither family that also comprises the Chinese (ancestral to the other zithers in the family), the Korean , and the Vietnamese . This variety of instrument came in two basic forms, a zither that had bridges and a zither without bridges.