The film has been identified as an unofficial remake of the
Akira Kurosawa film,
Yojimbo (1961), which resulted in a successful lawsuit by
Toho,
Yojimbo's production company. Kurosawa wrote to Leone directly, saying, "Signor Leone, I have just had the chance to see your film. It is a very fine film, but it is my film. Since Japan is a signatory of the Berne Convention on the international copyright, you must pay me." He and Toho received 15% of the film's revenue, and it is believed that Kurosawa earned more money from the financial settlement than he had made on his own film,
Yojimbo.