[3] Shepherd had previously met with Valerii on the set of The Best of Enemies and again on Day of Anger where he was Giuliano Gemma's dialogue coach.
[3] Valerii did not like Kumada's story for the film involving the mafia taking over a nearly bankrupt steel mill that is saved by a Japanese team.
[3] Valerii stated that it was absurd for the mafia to attempt to take over a company that was at a loss and read about a car engine that would work for less fuel was being tested on and suggested Kumada to make a story about that.
[4] On working with Kikkawa, who was a popular star in Japan at the time, Ring stated that he had limited English and felt bad for him on set.
[6] Co-production requirements demanded a Japanese lead, which was played by singer Koji Kikkawa which was meant to be a stepping stone into the Western market.