When the older composer died suddenly in 1955, leaving the scores to Kenji Mizoguchi's New Tales of the Taira Clan, and Kurosawa's I Live in Fear incomplete, Toho assigned Sato to finish them. His first original score was for Godzilla Raids Again in 1955. He wrote the music to all of Kurosawa's movies for the next decade, including Throne of Blood, The Bad Sleep Well, Yojimbo, Sanjuro, and Red Beard.
In 1955, when the older composer unexpectedly passed away without finishing Kenji Mizoguchi's New Tales of the Taira Clan and Kurosawa's I Live in Fear, Toho assigned Sato to complete them. His initial original score was for Godzilla Raids Again that year. Over the next decade, he composed music for all of Kurosawa's films, such as Throne of Blood, The Bad Sleep Well, Yojimbo, Sanjuro, and Red Beard.