Yasuko Agawa (阿川泰子) is a Japanese jazz singer who became the face of the early-1980s boom in female jazz vocalists. She was born Yasuko Satō (佐藤康子) in Kamakura on October 16, 1951, the only daughter of a Western-style painter, although the agency that launched her in 1978 listed her birth year as 1953. She moved to Nagoya in the third grade, set out to be a competitive swimmer, and spent a good deal of her childhood at home with an illness, listening to jazz and to American Forces broadcasts on the radio. She has said those years shaped her.

Her first career was acting. After high school she entered the 12th class of the Bungakuza theatre institute in Tokyo and left after a year. She then took small parts in Toho films and television, among them Evil of Dracula and The Prophecies of Nostradamus (both 1974), Terror of Mechagodzilla (1975) and the series Taiyō ni Hoero!, and used the stage name Tomoe Mari (麻里ともえ). She has been quoted as leaving because she objected to being cast in nude scenes as a minor player.

Jazz came through a Ginza club. In 1973 she met the clarinetist Shoji Suzuki there, and in 1974 she became the regular vocalist with his group, Shoji Suzuki and the Rhythm Aces, before moving on to solo engagements in Roppongi and Akasaka. Her debut album, Yasuko "Love-Bird", came out on Victor in January 1978, followed by Flyin' Over the same year. Both were built mainly on standards.

The breakthrough was Journey (1980). It is a set of jazz standards ("Sentimental Journey", "Take the 'A' Train", "Lullaby of Birdland", "Whisper Not") with the arrangements shared by Masanori Sasaji and Yasuaki Shimizu, additional arrangement by Norio Maeda, and Toshiyuki Honda among the saxophonists. It reportedly sold about 90,000 copies, mostly to office workers, at a time when a jazz vocal album was said to do well at 15,000; Wikipedia says it passed the earlier mark of about 50,000 held by Kimiko Kasai. The press gave her nicknames to match: "Sugar Voice", and the idol of the necktie-wearing salaryman set. Sunglow (1981), which includes "Skindo-Le-Le", was selected as one of the Best Ten Albums at the 23rd Japan Record Awards, and her first six albums are said to have sold some 900,000 copies between them. In 1981 she formed her own backing group, the Flamingo Big Band, and the single "She - Senior Dreams" became a television commercial song.

From 1982 she recorded in Los Angeles as much as in Tokyo. Fine! (1982) brought in the Brazilian group Viva Brasil and contains "New York Afternoon", whose cover has been described as a prototype for later "salon jazz vocal" interpretations. Gravy (1984) was cut in Los Angeles with David T. Walker on guitar, Victor Feldman on vibraphone and backing vocals from the Waters family and Miki Howard; its "L.A. Night" became her best-known recording. The same years produced her most conventional jazz records. All Right With Me (1985) is a trio-plus-horn session with the pianist Tommy Flanagan (who also arranged), bassist George Mraz and drummer Art Taylor, recorded in November 1984. Melodies (1986) put her with Ron Carter (credited as leader of the rhythm section), Roland Hanna, Lewis Nash and strings arranged and conducted by Hiromasa Suzuki. In 1986 Japanese Wikipedia lists her as winning the grand prize at the second Japan Jazz Vocal Award.

The rest of the 1980s and the 1990s mixed the two tendencies. Ms. Mystery (1987) was a Los Angeles studio record in the city pop vein, produced by David Garfield and Ronnie Foster with Nathan East, Michael Landau and Lenny Castro, and Ouro do Manaus (1988) was produced by Sérgio Mendes with Dori Caymmi, Russell Ferrante and Alex Acuña. From 1987 she co-hosted the Nippon Television talk show Oshare 30-30, singing a song each week, which kept her on screen for years. My Duke (1991) is an all-Ellington big-band album recorded in Los Angeles with Tom Ranier conducting and Harvey Mason, Snooky Young, Pete Christlieb and Jack Nimitz in the band. In Autumn (1993) used a Los Angeles rhythm section of David Benoit, John Clayton, Peter Erskine and Phil Upchurch, with Gerald Albright and Larry Bunker as soloists. Amizade (1994) was produced by Ivan Lins, and Beauty and the Beast (1994) paired her with the Tokyo trio of Tsuyoshi Yamamoto, Yoshio Suzuki and Toshio Osumi. Tea for Two (1997) was produced and mixed by Al Schmitt, with Greg Adams arranging and Harvey Mason on drums. The pop side shows too: a Burt Bacharach songbook (Close to You, 1996), a record of rock and pop covers produced by Pino Palladino (Echoes, 1996), and an R&B-flavoured album for Columbia (Other World, 2001).

A second life began in the 1990s, when DJs in London, among them Patrick Forge and Gilles Peterson, picked up her Victor records, and her version of "Skindo-Le-Le" became a club-jazz favourite. Re-Mode (Club Jazz Digs) (2007), produced by Tatsuo Sunaga, collected remixes by Nicola Conte, the Five Corners Quintet, Quasimode, Gerardo Frisina, Calm, Rasmus Faber and others. In the 2010s and 2020s she was reclaimed again as part of the city pop revival; "L.A. Night" appears on the 2019 Pacific Breeze compilation, and Victor issued Free Soul Yasuko Agawa in 2019 and Light Mellow Deluxe in December 2025. She remains active on stage. In November 2021 she sang "My Favorite Things", "Take the 'A' Train" and "Skindo-Le-Le" at a jazz vocal concert in Kawasaki that Billboard JAPAN reviewed, she hosts the Crossover Night series with Billboard Live, and she turned 75 on October 16, 2026.

Agawa is a stylist more than a technician. Her voice is light, close-miked and sweet, which is what the "Sugar Voice" label describes, and she sings standards in contemporary arrangements: Brazilian rhythms and strings on Sunglow and Soft Wings, Los Angeles soul-jazz and boogie on Gravy, a straight piano trio on All Right With Me, a big band on My Duke. Critics have described her music as taking in Latin, Brazilian and AOR elements and not being limited to jazz.

Her place in the jazz tradition rests on repertoire and on who she recorded with. The core of her catalogue is the American songbook and Ellington, and her sidemen include Tommy Flanagan, Ron Carter, Roland Hanna, Lewis Nash, George Mraz and Harvey Mason. Discogs files most of her standards albums under Jazz with the style "Vocal", and Japanese reference works call her a jazz singer. The competing identity is also real: she was marketed as an idol, hosted a television talk show, sang for commercials, and several albums (Ms. Mystery, Echoes, Other World, and the Bacharach set) belong more to pop and R&B than to jazz. Her sales and her television presence made her more famous than most of the Japanese jazz singers around her, and her approach is closer to the polished, adult-contemporary side of the jazz vocal tradition than to the improvising side.