At one point, Yung ( Ekin Cheng) asks Saori ( Cecilia Cheung) if she's really Japanese. This is a little in-joke with the filmmakers, since Saori is played by a Chinese actress.
In the script, the character of gang boss Takeshi Ito was meant to be a typical "calm, confident and arrogant yakuza boss". However, when Hiroshi Abe approached Jingle Ma about the idea of making him a very nervous kind of guy, Ma loved the idea and went with it.
The film's 2001 Laserdisc release in Japan was the last of its kind worldwide.