Director Hideo Gosha worked in development on Samurai Reincarnation (1981) for almost a year before his arrest on firearms charges lost him the job. Directorial duties were then offered to Kinji Fukasaku.
Samurai Reincarnation (1981) premiered in Japan at 6pm on 6 June 1981. A "666 Omen" designed to recall the publicity of The Omen trilogy at the time.
Became public domain in the US when the copyright wasn't renewed.
Director Kinji Fukasaku clashed with producer Haruki Kadokawa over which Jubei Yagyu novel was best to adapt. Fukasaku insisted that Oboro Ninpocho by Fûtarô Yamada was the only choice while Kadokawa insisted that Makai Tensho, also by Yamada, was the best novel to be adapted. It came as much embarrassment to Fukasaku and Kadokawa when they discovered that they were arguing about adapting the same story. Oboro Ninpocho was the original title when the story was serialized in the Osaka Shinbun newspaper from December 1964 to February 1965. Makai Tensho was the title given to the story when it was published in novel form in 1967.
Shiro Amakusa is named after a real Christian Samurai.