* ActorInspiredElement: The scene where Charlie sings on stage at the night-club with Masahiro was not in the script. Creator/AndyGarcia conceived the scene to add extra emotional involvement to his character, before he is brutally murdered in the following scene.
* CaliforniaDoubling: Because the production's work visa in Japan ran out, the climactic farm scenes were filmed in Napa Valley, California. According to Creator/RidleyScott, the work visa complications came about due to Japanese bureaucracy. As a result of these experiences, Scott has refused to make any further films in Japan to date.
** Three other scenes had to be shot in Los Angeles: the airport sequence, the nightclub, and [[spoiler:Charlie's death scene]].
* FoilerFootage: At the end of the movie Nick apprehends Sato, although there is a moment when he is torn between arresting and killing him. Creator/RidleyScott also shot an alternative ending where Nick impales Sato on the spike.
* HeyItsThatPlace: Sugai's house was the Ennis-Brown House, which is situated at 2655 Glendower Avenue, Los Feliz in Los Angeles, California. Creator/RidleyScott had previously used the dwelling for Deckard's apartment complex in ''Film/BladeRunner''.
* InMemoriam: The film is dedicated to Japanese actor Yusaku Matsuda, who refused treatment for his bladder cancer to play Sato. He died just weeks after the film's North American premiere.
* InspirationForTheWork: Screenwriter Craig Boloting got the idea for the film while visiting a friend in Japan. While standing on a street corner, he saw big American cars pass by. His friend told him that they belonged to the Yakuza.
* MultipleLanguagesSameVoiceActor: In the Japanese dub:
** Guts Ishimatsu reprised his role as Katayama for the Fuji TV broadcast.
** Shigeru Kamiyama voiced Ohashi for the home media release as well as the Fuji TV broadcast.
* PlayingAgainstType:
** In Japanese cinema, Ken Takakura was well known for regularly playing Yakuzas, while Yûsaku Matsuda was well known for regularly playing detectives. Here, Takakura plays a cop and Matsuda plays a Yakuza.
** Yuya Uchida, who plays Sato's AffablyEvil right-hand man, was a pop crooner likened to a Japanese Music/JohnLennon.
* ReleaseDateChange: Originally touted for an August 1989 theatrical release, Creator/{{Paramount}} pushed the release date back to early fall, on September 22, to avoid that year's crowded summer season.
* SwanSong: This was Yûsaku Matsuda's last film role. He knew he had bladder cancer and that his condition would be aggravated by acting in the movie, but he elected to do so anyway, unbeknownst to Creator/RidleyScott, reportedly saying, "This way, I will live forever."
* WhatCouldHaveBeen:
** Creator/PaulVerhoeven was originally going to direct, but he dropped out in favour of ''Film/TotalRecall1990''.
** Creator/JeffBridges, Creator/KevinCostner, Creator/WillemDafoe, Creator/RichardDreyfuss, Creator/HarrisonFord, Creator/MelGibson, Creator/RutgerHauer, Creator/MichaelKeaton, Creator/MichaelNouri, Creator/RonPerlman, Creator/KurtRussell, Creator/ArnoldSchwarzenegger, Creator/SylvesterStallone, Creator/PatrickSwayze, Creator/PeterWeller and Creator/BruceWillis were considered for Nick Conklin.
** Creator/JackieChan was first approached to choreograph action scenes and play Koji Sato, but declined the role because he didn't think audiences would want to see him play a villain.
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