It is said that Mifune participated in the film because he was living in the same apartment house where Okamoto had been living since he was an assistant director, and as they were getting on well with each other, Mifune took part in the film with good grace to celebrate Okamoto's promotion to director.
岡本が助監督時代から同じアパートに住み、仲がよかったため、岡本の監督昇進を祝って出演を快諾したからだという。