Hidehiko Matsumoto — known throughout his career as "Sleepy," a nickname given to him by an American soldier while he was playing at a US military camp in the years right after the war — was born in Okayama Prefecture on October 12, 1926, and raised in Fuchū, Hiroshima. He became a bebop saxophonist in the late 1940s, part of the pioneer generation that built Japan's postwar jazz scene largely inside occupation-era military clubs before it had anywhere else to exist. He played in early bands including CB Nine and The Six Josés, and in The Big Four alongside drummer George Kawaguchi and composer Hachidai Nakamura — two other figures foundational to how Japanese jazz got its start.

By 1959 he had joined Hideo Shiraki's small ensemble, and his international profile grew on its own merit rather than as novelty: a 1963 appearance with Gerald Wilson at the Monterey Jazz Festival, and a 1964 collaboration with Toshiko Akiyoshi that also produced a session billed to "Toshiko Mariano and Her Big Band," putting him in a Tokyo rhythm section with Paul Chambers and Jimmy Cobb — Miles Davis's own bassist and drummer. He began leading his own ensembles the same year.

The single most striking fact of his career: on July 22 and 24, 1966, during John Coltrane's final tour of Japan — the tour that produced the Live in Japan album — Matsumoto played with Coltrane's quintet onstage in Tokyo. No commercial recording of his specific participation survives, but the dates themselves are documented against a well-known, thoroughly chronicled tour.

His own catalog as a leader runs deep, over fifty credited dates on Discogs spanning nearly four decades: Sleepy Matsumoto and Latin Carnival (both 1958, King Records) through a run of "Jazz Battle" tenor-showdown records in the 1970s (K. Saijo vs. H. Matsumoto, 1976; Opus de Four Tenors, 1977) and The Session / Sleepy Meets the Great Jazz Trio (1980), pairing him with Japan's premier modern-mainstream rhythm section. He remained active into his own late sixties and seventies, releasing Eternal Dreams on Meldac Jazz in 1997. Sidemen across his groups over the decades included Takeshi Inomata, Akira Miyazawa, George Otsuka, and Isao Suzuki.

He stayed connected to later generations of Japanese musicians throughout his career — a saxophonist who'd learned the music playing for occupying American forces in the late 1940s still recording alongside players two generations behind him, including Takeru Muraoka, Ryo Kawasaki, Motohiko Hino, and Masahiko Togashi. He died in Tokyo on February 29, 2000, at 73.

Matsumoto's catalog spans real stylistic range across his four-decade recording career: hard bebop in the 1940s-50s, Latin-flavored sax records in the same period, straight-ahead swing collaborations with visiting American musicians (Gerald Wilson, and — however briefly — Coltrane), and, from the mid-1970s on, a run of tenor-battle "Jazz Battle Series" records pitting him against other Japanese saxophonists of his generation.