Luna Watanabe (渡邉瑠菜, Watanabe Runa in Japanese order) is an alto saxophonist, vocalist and singer-songwriter born on 28 November 2002 in Yamanakako, a village on Lake Yamanaka in Yamanashi Prefecture, in the Fuji Five Lakes area. She started on an upright piano at her grandmother's house in elementary school and played by ear. In junior high she had to choose between the art club and the big band club, heard the band at the club introduction, and took up the alto saxophone after being struck by an older student's solo. At Fuji Gakuen High School, the only school in Yamanashi with a big band at the time, she played lead alto and acted as MC, appearing in about 70 shows a year. At 14 she won the Outstanding Player Award and the Chairman's Award at the 2017 Student Jazz Festival East Japan, and she later added a Best Play Award at the Hamamatsu Jazz Week student festival and an award at the Asakusa Jazz Contest.

She studied in the jazz course at Showa University of Music (昭和音楽大学) in Kawasaki. Her main teacher there was Masato Honda, and from her third year she also studied with Masanori Okazaki and Kazuhiko Kondo and took lessons outside school with the saxophonist Osamu Koike. While still a student she began working professionally: she took part in Honda's B.B.Station, played the Singapore concert of the Blue Note Tokyo All Star Jazz Orchestra, and joined Toshiki Kadomatsu's tour and recording work.

Her breakthrough came at the 54th Yamano Big Band Jazz Contest, held at Kita Toppia Sakura Hall in Tokyo on 30 and 31 August 2023. Showa's Lily Jazz Orchestra took the top prize, and she was named Best Soloist, which her biographies describe as the first time a woman had won that individual award. (Some artist biographies give the year as 2025; the contest results and the university's announcement date it to August 2023.) The band placed second in 2024.

2024 was her busiest student year. She was chosen through a public call as a BRIDGE Artist for Kawasaki Jazz 2024, the festival's tenth edition, when she was a 22-year-old fourth-year student, and the city of Kawasaki gave her its Culture Award for young artists, the Azalea Radiance Award (川崎市文化賞アゼリア輝賞). The festival announcement said she would join the pianist Hiroko Kokubu's trio at LAZONA Kawasaki Plaza Sol on 8 November, and her own year-end blog post lists a performance with Kokubu after a rained-out event. She also played lead alto at Sapporo City Jazz with Eric Miyashiro's Blue Note Tokyo All Star Jazz Orchestra, and was named an ambassador for Yamanashi Prefecture and for the Fuji Five Lakes region.

After graduating in the spring of 2025 she made her first leader appearance at BLUE NOTE PLACE in Tokyo on 16 July 2025, singing and playing alto with a quintet of drums, bass, piano and guitar; one of the pieces she arranged herself was Herbie Hancock's "Cantaloupe Island". On 24 September 2025 Eric Miyashiro released the limited-edition vinyl album Blue Horizon on Orange Lady, with her on alto saxophone and flute on three tracks ("Blue Horizon", "Catch the Rainbow" and "Spain"). In December 2025 she played alto in the Persona 5 Special Big Band, whose concerts at the Shinjuku Bunka Center are preserved on the two-CD set PERSONA 5 Special Big Band Concert 2025 (Atlus Game Music, 2026); Miyashiro is also in that band. Her artist biography also lists the Montreux Jazz Festival 2025, and the Japan edition of that festival (Yokohama, 5 to 7 December 2025) had the Persona 5 Special Big Band on its main-stage day, 7 December.

Her first release under her own name came in 2026: four singles between 20 February and 13 March, then the album RETURN TO INNOCENCE on 27 March 2026, ten songs that stream as J-pop rather than jazz. She is, at 23, very early in her career, and the public record of her jazz playing is mostly live performance, contest results, session credits and big-band chairs rather than recordings of her own.

Watanabe comes out of the Japanese school big-band system, where the lead alto chair is a section leader's job: phrasing for the whole saxophone row, tuning the sound of the band, and then stepping out to solo. That is the chair she held in high school, in Showa's Lily Jazz Orchestra, and with the Blue Note Tokyo All Star Jazz Orchestra at Sapporo City Jazz. Her solo prize in 2023 is the same skill seen from the front of the stage.

Her listening runs through Japanese jazz-fusion. The February 2024 issue of the saxophone magazine THE SAX (vol. 116) featured her as a model performer on transcriptions of fusion tunes by T-Square (then billed as The Square), by Malta and by the saxophonist Sadao Watanabe; no family connection to Sadao Watanabe is stated in any of her biographies. Her teacher Honda is himself a veteran of that world, and the horn she plays is a Yamaha Custom alto, the YAS-875EXS.

What sets her apart from most big-band prizewinners is that she sings. At her BLUE NOTE PLACE debut she both sang and played, and Japanese Wikipedia, drawing on her interviews, describes her aim as singing through the saxophone, to the point of writing lyrics for instrumental tunes so she can shape the phrasing. Her own releases take that to song form: RETURN TO INNOCENCE is a singer-songwriter album tagged J-pop on Apple Music (the singles are tagged R&B/soul, J-pop and alternative), while her artist bio says her music is "rooted in jazz but not limited to the genre". For that reason this profile treats her as a jazz-trained saxophonist whose recorded leader work currently sits closer to pop; the jazz evidence is her education, awards, big-band work and the sideman credits below.