[1] Yamaguchi was born in Nagoya as the illegitimate child of a wealthy restaurant owner and a waitress.
[2] She dropped out of high school at 16 and opened a coffee shop named "Yoko" with backing by an elderly widower.
She became his mistress, known to members of his crime family, the Ando-gumi (ja:安藤組), as "Hime" ("princess").
[3] When Ando was on the run from the police in 1958 for having a hitman shoot businessman Hideki Yokoi, Yamaguchi hid him in her apartment in Yoyogi.
[1] Yamaguchi penned another hit with "Brandy Glass", performed by actor and singer, Yujiro Ishihara.