!! Trivia for the manga and OVA:

* DubNameChange: Yo's handler Huáng is re-named Koh in the English dub, a change that was later carried over to the live-action film.

!! Trivia for the live-action film:

* BillingDisplacement: {{Creator/Mako}} is billed above Tchéky Karyo, but [[spoiler:has around six minutes of screentime before being killed off in dramatic fashion.]]
* [[CaliforniaDoubling Vancouver Doubling]]: The live-action film is set in San Francisco, Shanghai, New York, Hokkaido, and Vancouver. The entire film was shot in the latter.
* FakeNationality:
** Yo (Japanese) is played by American actor Creator/MarkDacascos, though he does have partial Japanese ancestry.
** Canadians Emu and Netah are played by Julie Condra (American) and Tchéky Karyo (French), respectively.
* RomanceOnTheSet: Stars Creator/MarkDacascos and Julie Condra later married.
* SameLanguageDub: Julie Condra and Creator/TchekyKaryo were both dubbed, Condra by Creator/DeborahKaraUnger and Karyo by Creator/RonPerlman. Director Gans justified the decision by saying he wanted Emu to have a deeper, sultrier voice, and felt that Karyo's French accent didn't fit his character. Gans had originally approached Unger for the role of Emu, but she turned it down due to being busy with pre-production for ''{{Literature/Crash}}''.
* ThrowItIn: Creator/MarkDacascos and Christophe Gans improvised the choreography of the climactic swordfight in the days leading up to filming.
* WhatCouldHaveBeen:
** Creator/JasonScottLee was originally wanted for the role but he had a three-picture obligation for Universal Pictures and could not commit to the project. Creator/MarkDacascos lobbied for the part and eventually went on to became Christophe Gans' actor of choice for future and upcoming films.