Kazuki Katsuta (勝田一樹, Katsuta Kazuki in Japanese order) is an alto and soprano saxophonist from Kanagawa Prefecture, born on September 3, 1966. He has worked on two tracks that seldom share a biography: as the saxophonist of the fusion band Dimension, which has made an album almost every year since 1992, and as the horn player that Japanese pop and rock acts call when a record needs a saxophone solo.

According to Japanese Wikipedia, he began in 1988 and 1989, joining Takeshi Hayama and others as support players on a tour by the singer-songwriter and producer Tetsuro Oda (織田哲郎). From the BE NATURAL tour of 1990 he went on to play almost every tour by the band TUBE, and Oda, the singer Seiichiroh Kuribayashi and the members of TUBE all use his nickname, "Katsuo." His name starts turning up on Discogs credits in the same years, on Rhizome-label records by Kuribayashi (La Jolla, 1989) and by the guitarist Takashi Masuzaki, whose solo albums Speaks (1990) and Escape (1991) both list him on saxophone.

The step from hired hand to band member came with Dimension. Masuzaki formed the group in 1992, and its debut mini-album, Le Mans, came out on Rhizome on June 24, 1992, with Masuzaki on guitar, Akira Onozuka on keyboards, Tomohito Aoki on bass, Yuichi Togashiki on drums and Katsuta on saxophone. First Dimension followed in January 1993, and the band kept to a steady schedule after that: albums numbered in their titles through the 1990s, a double live album, 13th Dimension Live Millennium (2000), with Akira Jimbo on drums and a feature solo track for each member, and a move from Rhizome to Zain Records in 2003 with 16th Dimension. In 2007 20th Dimension "-Newish-" brought in the bassist Chris Minh Doky and the drummer Lionel Cordew as guests. In 2020 the band announced that it would carry on as a duo of Masuzaki and Katsuta with rotating rhythm players, and the 35th album, 35, was released on June 24, 2026.

The outside work ran alongside. Discogs credits him with saxophone on records by the singer Maki Ohguro from 1992 onward, on TUBE's "湘南 My Love," on a track of B'z's Brotherhood (1999), and on two tracks of Toshiki Kadomatsu's Forgotten Shores (2025). He is credited on alto saxophone on the Mario Kart 8 soundtrack, and Japanese Wikipedia notes that he joined Dreams Come True's THE DREAM QUEST tour of 2017 and 2018 and, in 2019, shared the stage with a brass section that included Greg Adams, formerly of Tower of Power. In the jazz-fusion circle he is credited on Jimsaku's Navel (1994) and as soloist on Dispensation (1996), on Tetsuo Sakurai's A Gate of the 21st Century (1999) and live album TLM20 (2000), and on a track of Isamu Ohashi's No Edit (1998). He also played in the group RX, on Zeitmesser (2000), Elements (2001), Kiss of Life (2002) and the DVD Live in London with John Wetton, and in the fusion band Kkjam, whose two albums, Kkjam (2006) and KKJAM II (2008), were released by Hiyo Records.

Under the name Jafrosax he made a separate body of work from 2003. The Jafrosax records were issued through Konami and Pantone Music and lean toward club jazz and house; they include the album Jafrosax (2004), Jafrosax 2 (2005), Jafrosax 3 (2006), Jafrosax 4 (2007), and the collection New Standard Of The Future (2006), with guest singers including Vikter Duplaix and Yukimi Nagano.

His own name came to the front rather late. His first solo album, Kazuki Katsuta (Zain Records, March 5, 2014), put him at the head of a band with Mitsuru Sutoh and Teppei Kawasaki on bass, Hiroyuki Noritake on drums, Masuzaki on two tracks and Onozuka on keyboards. According to the Dimension site's own profile, it topped the Amazon, iTunes and Oricon charts for Japanese jazz artists. Visualize (2016), Saxree (2018) and Neo (2024) followed on the same label.

Katsuta works in the Japanese fusion tradition, with the saxophone out front of a band built around guitar, keyboards and a rotating rhythm section. Japanese Wikipedia says he admires David Sanborn. Discogs files almost every Dimension album under Jazz with the style Fusion, with Smooth Jazz or Jazz-Rock added on some, and his solo records the same way, with Neo tagged Jazz-Rock. The titles on Neo, such as "Dance With Punks" and "Thunder Sax," suggest a harder-edged turn than Visualize or Saxree.

The picture has a second side that should be stated plainly. A large share of the credits attached to his name are pop and rock sessions and tours for acts such as B'z, TUBE and Dreams Come True, plus game and anime soundtracks, and the Jafrosax project sits in club-jazz and house territory rather than fusion. The jazz identity rests on Dimension, whose 35 numbered albums are tagged Jazz and Fusion, on his four solo records, and on the fusion sessions with Jimsaku, Tetsuo Sakurai and Isamu Ohashi.