Kiyoto Fujiwara (藤原清登, Fujiwara Kiyoto in Japanese order) was born on 31 August 1953 in Takamatsu, in Kagawa Prefecture on the island of Shikoku. Both of his parents were musicians, and he took up the double bass at 16. He studied with Seiichi Imamura, a professor at the Tokyo University of the Arts. In 1974 he left for the United States to study at the Berklee College of Music in Boston, where, according to his official biography, he played with George Russell and Ran Blake.

He moved to New York in 1975 and began working professionally there. His biography says his career started that year with the Horace Silver Quintet; no Silver recording credit turned up in the record listings, so that claim rests on his own account. The earliest bass credits that do show up are from 1976: Joe Lee Wilson's Shout For Trane (recorded in New York on 7 July 1976 and issued in Japan by Whynot/Trio) and Clifford Jordan's Remembering Me-Me (Muse, recorded in May 1976, with Wilbur Ware as the other bassist). His partial performance list names Wilson and Jordan (both 1975 to 1979), Andrew Hill (1976), Sunny Murray and Woody Shaw (1977), Jaki Byard (1977 to 1981), Jackie McLean (1978), Eddie Jefferson (1979), Shamek Farrah (1980), Sonny Fortune (1980) and Terumasa Hino (1981). On record he is credited on two Shamek Farrah dates, The World of the Children (Strata-East, 1977) and La Dee La La (Ra, 1980), and on Love Walking by the Japanese pianist Teruhiko Kataoka (Whynot, 1977). Most of the names on that list come from his biography rather than from session credits.

In 1980 he entered the Juilliard School, studying with John Schaeffer, a former principal bassist of the New York Philharmonic. He earned a graduate diploma in 1983 and a post-graduate diploma in 1984, and was chosen for the Juilliard Orchestra's European tour in 1983. The jazz work continued alongside. From 1984 to 1986 he played with the German vibraphonist Gunter Hampel, and Fresh Heat - Live at Sweet Basil (Birth, recorded 4 February 1985) has him on bass in Hampel's New York orchestra. He was also a regular with Fred Ho's Afro-Asian Music Ensemble (his biography gives 1986 to 1990): he is on the Soul Note albums Tomorrow Is Now! (1985), We Refuse To Be Used And Abused (1988) and The Underground Railroad To My Heart (1994), and on later Ho records. In 1986 he also played with the Archie Shepp sextet, according to his biography.

In 1984 he formed his own group, Manhattan Graffiti Four (MG4), with the alto saxophonist Kenny Garrett, the pianist Peter Madsen and the drummer Shunsuke Fuke. Garrett, Madsen and Fuke are all credited on the group's records, starting with MG4 (recorded 3 and 4 October 1987 in New York), and the group toured Japan repeatedly from 1988. It made its first European appearance in Milan in 1987, and that year he also joined the pianist Fumio Karashima's trio for his first tour of Japan. A run of albums followed under his own name or the group's: Manhattan Tango (Alfa Jazz, 1990) and 60 Miles High (TDK, 1993), the latter with Garrett on soprano saxophone and Thomas Chapin and Allen Won among the reeds. His biography also lists 1994 to 1997 with the saxophonist Thomas Chapin. He is the bassist on Chapin's You Don't Know Me (Arabesque, recorded in August 1994) and on the live Haywire (Knitting Factory, 1996), where Chapin's trio is joined by strings. He also played with Michel Legrand in 1996, again by his own account.

The 1990s are when he became widely known in Japan. Bass (1996), recorded at the American Academy of Arts and Letters in New York on 8 December 1995, is an unaccompanied solo CD. King Records then took him on, and a series of piano-trio albums for its Paddle Wheel, Electric Bird and Seven Seas lines followed, with Madsen and Fuke: Modern Bass (1996), Concierto De Aranjuez (1997), Duke & Mingus (1998), The "In" Crowd (2002) and, with the pianist Davide Santorsola in Madsen's place, Mattinata (2004). He also made Bass & Bass: Vino Rosso (1999), a duo of two basses, one in each stereo channel, with Yoshio Suzuki. Gargantua (2000) is another solo record, which Japanese Wikipedia says was made at a monastery in Seuilly, in France. His tracks also appeared on King's compilations The King of Bass (1999) and The King of Bass II (2000), and in 2000 the Japanese magazine Swing Journal voted him number one in its bass category. The nickname that goes with it, the "King of Modern Bass" (モダンベースの王者, or 低音王), has followed him since.

Jump Monk (2008), recorded in December 2007 by a band of four reeds, trumpet and rhythm section billed as the Jump Monk Orchestra, is a record of Mingus, Monk and his own pieces. In 2011 he began working with Jump Monk BBS (Bass Band Special), a large ensemble built around several double basses. In 2013 he founded his own label, Gargantua, whose first release was the trio album I'll Catch The Sun (2013, with Santorsola and Fuke). Koffee Crush (2017, with the pianist Shinichiro Imamura and the drummer Masashi Tomikawa) and Songbook55 (2023, with the pianist Mayuko Katakura and the drummer Sebastiaan Kaptein, a set of his own compositions) followed on the same label. Outside his own records he has recorded with the pianist Masahiro Sayama (2016) and with the Italian percussionist Andrea Centazzo: first in a trio with the saxophonist Akira Sakata on Bridges (Ictus, 2012), then in a trio with the alto saxophonist Masayo Koketsu on Mystic River Of The Universe (Ictus, 2025), recorded live at the Jazz Art Sengawa festival in Tokyo on 8 November 2024.

He has also written and taught. His book 僕がジュリアードとバークリーで学んだこと (What I Learned at Juilliard and Berklee) was published by Kawade Shobo Shinsha in October 2018, and he taught at the Senzoku Gakuen College of Music. In Takamatsu he began a concert series called Jazz Is!! in 2022, held a Jazz Is BBS event in 2024, and in 2025 became music director of the new Takamatsu International Jazz Festival (Takamatsu Jazz Summit); his website reports that a second edition has since been held. He is active today as a leader and teacher.

Fujiwara plays the double bass as a lead voice. Many of his records are bass-first piano trios, and the titles of three of them, Modern Bass, Bass and Gargantua, say what the project is. His Juilliard training shows in a bowed solo repertoire that includes Bach's Sarabande from the Partita BWV 1013, the aria from I Pagliacci and Villa-Lobos's "The Little Train", and it sits beside the hard-swinging language of Charles Mingus, Duke Ellington and Thelonious Monk, to whom he has devoted whole albums. A 2023 JazzTokyo review of Songbook55 compares his direction to Mingus and Charlie Haden, citing his strong tone and the combination of composing and bandleading.

His repertoire runs across three kinds of material. The trio albums mix Ellington and Mingus tributes, the Latin warhorse "Concierto De Aranjuez", standards like "Autumn Leaves" and "Summertime", and his own tunes such as "Manhattan Tango", "Boy and Beauty", "Rain" and "Vibes", which come back on almost every record. The solo records use bowed arrangements of classical pieces, pop songs ("Yellow Submarine") and Ellington's "Come Sunday". And the later Gargantua-label records add pop and rock numbers such as "I'm A Believer", "20th Century Boy" and "These Boots Are Made For Walkin'". Deep Paradise (Gunboy, 2005), a vocal record with the singer Lia inspired by the anime Armored Trooper Votoms, is a side project in a catalogue that is otherwise jazz.