The is a traditional Japanese musical instrument, a zither

Zither

The zither is a musical string instrument, most commonly found in Slovenia, Austria, Hungary citera, northwestern Croatia, the southern regions of Germany, alpine Europe and East Asian cultures, including China...

 with seventeen strings. It is a variant of the koto

Koto (musical instrument)

The koto is a traditional Japanese stringed musical instrument, similar to the Chinese guzheng, the Mongolian yatga, the Korean gayageum and the Vietnamese đàn tranh. The koto is the national instrument of Japan. Koto are about length, and made from kiri wood...

, which traditionally has thirteen strings.

The instrument is also known as jūshichi-gensō (十七絃箏), "seventeen-stringed koto," or "bass koto" (although kotos with a greater number of strings also exist). The jūshichi-gen was invented in 1921 by Michio Miyagi, a musician who felt that the standard koto lacked the range he sought. His seventeen-stringed creation, sometimes described as a "bass koto", has a deeper sound and requires specialized plectra

Plectrum

A plectrum is a small flat tool used to pluck or strum a stringed instrument. For hand-held instruments such as guitars and mandolins, the plectrum is often called a pick, and is a separate tool held in the player's hand...

 (picks worn attached to the player's fingers with which the strings are plucked). Though his original jūshichi-gen was considerably larger than a normal koto, seventeen-stringed koto of a normal koto size are more common today; these presumably do not have as deep a sound.

Though Miyagi also invented an 80-string koto

80-string koto

The 80-string koto was an invention of Japanese composer Michio Miyagi which appeared In 1923. He added 67 strings to the traditional 13 string koto design, creating an instrument much like a western harp....

 and a short koto, these did not catch on and spread as the jūshichi-gen did. It is still used today in various forms of traditional music; some of its more prominent exponents include Kazue Sawai

Kazue Sawai

is a Japanese koto player noted for her performance of contemporary classical music and free improvisation.She began studying, at the age of eight, with Michio Miyagi. She later graduated from the Tokyo National University of Fine Arts and Music....

, Shoko Hikage, and Miya Masaoka

Miya Masaoka

Miya Masaoka is an American musician and composer who performs on the 17-string Japanese koto zither, often augmenting it with string preparations and electronic triggers...

. The members of the Japanese band Rin'

Rin'

Rin is a Japanese pop group which combines traditional Japanese musical instruments and style with elements of modern pop and rock music. It is a female trio of Tokyo National University of Fine Arts and Music alumni who graduated in 2003...

are among those who use the instrument in modern popular music.