Kōji Mitsui, originally Mitsui Hikohide, was a celebrated Japanese actor whose performances left an indelible mark on the film industry. Best known for his role as the charming playboy Kisaburo in Akira Kurosawa's acclaimed film *The Lower Depths* (1957), Mitsui's talent earned him prestigious accolades, including Best Supporting Actor at the Mainichi and Blue Ribbon Awards. His collaboration with cinematic giants like Kurosawa and Yasujiro Ozu, particularly in *The Hidden Fortress* (1958), showcases his versatility and depth as an actor, making these titles highly sought after by collectors. Mitsui's career took a turn when he went freelance in 1960, branching out into television and stage performances, but his iconic roles in post-war Japanese cinema continue to resonate with collectors today. His films, especially those featuring his distinct performances, are treasured for their historical significance and artistic merit, solidifying Mitsui's legacy as a key figure in the evolution of Japanese film.