Toshiro Mifune was George Lucas's original pick for Obi-Wan Kenobi; his role as Gen. Rokurōta in The Hidden Fortress was the inspiration for Kenobi's character in the first place. Incredibly, before he turned down the role (Mifune worried the sci-fi story would look cheap and make samurai look silly), George Lucas was even toying with shooting the entire film in Japanese.
