Also known as "I Left My Mind in San Francisco."
In the International versions that were used on the Geneon DVDs and on streaming sites, the licensed song that Zenigata was listening to while he was sleeping from 7:58-8:10 was replaced due to copyright reasons. Due to the sound mixing, the replaced song is at a very low volume and is two seconds shorter. This affects both the English dub and the Japanese soundtrack.
The voice actors of the doctor and Zenigata have connections to Lee Van Cleef in different languages. Goro Naya dubbed Van Cleef in the Japanese dubs of two of the Dollars Trilogy films, while Simon Prescott voiced Van Cleef's character Angel Eyes in restored scenes for the 2002 DVD release of The Good, the Bad and the Ugly , after Van Cleef died in 1989.
The store that is behind Zenigata when he leaves the clinic says "Conan Doyle Co." a reference to the Sherlock Holmes writer Arthur Conan Doyle.
The licensed song that Zenigata was listening to while he was sleeping in various versions, including the Spanish and Italian versions, was "Kita no Yado Kara" by Harumi Miyako.