Actress Kaho Minami, who plays the Madam, is married to actor Ken Watanabe.
Masi Oka was originally cast in the title role but dropped out just months before principle photography.
The family crest that the Ronin wears belongs to the family of executive producer Keita Ideno.
Adam LaVorgna played Robbie Palmer in 7th Heaven from 1999 though 2002.