Musician Masashi Sada has written roughly 650 songs over a career spanning five decades. | ANNA PETEK

Masashi Sada is one of Japan’s most beloved and prolific musicians, with a catalog of roughly 650 self-penned songs and a career spanning five decades. Also an accomplished author with numerous books to his name, Sada brings a literary sensibility to songwriting, penning lyrics that pierce the heart.

Born in Nagasaki in 1952, Sada emerged as a purveyor of kayōkyoku , Japanese standards popular from the 1920s to the ’80s. He scored his first No. 1 hit in 1977 with “Amayadori,” which translates to “taking shelter from the rain.”

That song kicked off a golden run that continued into the early ’80s. Tracks such as “Kanpaku Sengen” ("Declaration of the Chancellor") are so ubiquitous that most Japanese people of a certain age can recite their lyrics.…