Monday Michiru was born in Tokyo on August 19, 1963, to pianist Toshiko Akiyoshi and saxophonist Charlie Mariano. She began recording under her mother's surname, as Michiru Akiyoshi, in the late 1980s — Mangetsu (1991, Virgin Records Japan) is the record from this period whose cover stands in for a photo on this profile — before establishing the Monday Michiru identity she has carried since, and became one of the pioneers of the Acid Jazz movement in Japan in the early 1990s.

Her catalog since is enormous and genre-crossing rather than straight-ahead: dance and club remixes, soul, pop, and later a real Brazilian-music direction (Brasilified, 2013; Brasilified Nights, 2014). She recorded with J-pop unit m-flo (A.D.D.P., 2005) and has been remixed and reworked by DJs and producers across two decades of club culture. Discogs credits her with more than 75 leader releases across a recording career running essentially without a gap from 1988 through 2022.

Her jazz lineage returned to the foreground twice, explicitly, on record: Hope (希望, 2006), billed jointly to Toshiko Akiyoshi and Monday Michiru, and Jazz Conversations (The Other Side of Monday Michiru) (2015), again with her mother. These are genuine adult collaborations between a jazz pianist and her genre-crossing daughter, not sentimental tribute tracks — direct, dated evidence of two generations of the same family recording together on purpose, decades into both of their careers.

She lives in New York City with her husband, jazz trumpeter Alex Sipiagin, and their son.

Monday Michiru's music is deliberately genre-fluid — Acid Jazz's harmonic jazz vocabulary run through dance-floor rhythm sections, soul and pop songwriting, and, in her later career, a substantial Brazilian-music influence. Her direct recordings with Toshiko Akiyoshi are the clearest documented point where her catalog returns explicitly to straight jazz.