Kazuo Ikehiro got his start as an assistant working for directors like Kenji Mizoguchi and Kon Ichikawa. He always had a strong preference for working in jidai-geki and says that he only did a number of modern-day yakuza films because of studio demands. Ikehiro developed a gritty, unconventional style that made him an excellent match for Zatoichi and the antihero screen personae of Raizo Ichikawa.
Possibly his greatest achievement came with Raizo, when he played an instrumental part in the Nemuri Kyoshiro series. The first three movies had been fairly straightforward chambara adventures, but with 1964's Sword of Seduction, Ikehiro steered the series into the surreal and stylistically outrageous extremes that made the Son of the Black Mass so legendary.