According to the announcement, 73-year-old Akira Kamiya, the original anime voice cast of Ryo, turned down the offer because it was a live-action work (In the 1993 Hong Kong live-action adaptation, the star Jackie Chan’s fixed Japanese dub cast Hiroya Ishimaru voiced Ryo).
As special guest voice, Kamiya and Kaori’s original anime voice cast, Kazue Ikura, will play yet-revealed characters.
Meanwhile, the anime’s three original voice cast: Harumi Ichiryusai/Yoko Asagami as Hélène Lamberti/Saeko Nogami, Tessho Genda as Mammouth/Umibouzu, and Hideyuki Tanaka as Tony Marconi/Hideyuki Makimura voice their characters in the live-action as well.