Ichigenkin

The ichigenkin (一絃琴?, literally "one-string zither", also sumagoto) is a Japanese single-stringed zither. Its slender, flat body is carved from kiri (Paulownia tomentosa) wood. Its silk string is plucked with a pointed tubular plectrum placed on the index finger of the right hand while the rokan (a tubular ivory device similar to a guitar slide placed over the middle finger of the left hand) slightly depresses the string—though not so hard that it presses against the hardwood soundboard—to vary the pitch. As with the Chinese guqin, from which it was likely originally adapted, the ichigenkin has no frets, so sliding tones are an important part of the technique of the instrument.