This is the first Zatoichi film to feature a flashback. The flashback also utilises a discolouration special effect which was never used in a Zatoichi feature before either.
While this is the nineteenth Zatoichi film, it also marks the fifth Zatoichi film to be directed by Kenji Misumi, since his work upon the first film in the series, 'Tale of Zatoichi' (1962), the eighth film in the series 'Fight, Zatoichi, Fight!' (1964), the twelfth film in the series 'Zatoichi & the Chess Expert' (1965) and the seventeenth film in the series 'Zatoichi Challenged' (1967).
The film makes several references to the Yakuza Code. This was also known as the Jingi, and was the Yakuza's Code of Ethics. It is a written code of conduct that by the law of the Yakuza has been followed for the past several hundred years. Depending on the Oyabun or Father figure (Chariman) of a Yakuza Clan, one could be removed from a clan by disregarding one of these rules. Or as we see in the film - have one's life made forfeit.
Zatoichi's katana is a shikomizue. This is a sword which is concealed within a wooden cane, thus the cane itself is both handle and scabbard.
The hat which the Yakuza are seen with in the film are sandogasa. Translated this means 'travel hat'.