 Gilbert had chosen <unk> Tamba after working with him in The 7th Dawn . A number of actual martial arts experts were hired as the ninjas . The two Japanese female parts proved difficult to cast , due to most of the actresses tested having limited English . Akiko Wakabayashi and Mie Hama were eventually chosen and started taking English classes in the UK . Hama , initially cast in the role of Tanaka 's assistant , had difficulty with the language , so the producers switched her role with Wakabayashi , who had been cast as Kissy , a part with significantly less dialogue . Wakabayashi only requested that her character name , " <unk> " , be changed to " Aki " . 
