"Variety reports that Ken Watanabe will star in Eastwood's Red Sun, Black Sand, the Japanese companion piece to his Flags of Our Fathers.

Steven Spielberg is a producer on both films, which tell the story of the famous WWII battle from each side. DreamWorks and Warner Bros. are partnering on the films, which will have a staggered release later this year. ""Flags"" is expected to be released first.

Eastwood, who is in post with ""Flags,"" will shoot the companion entirely in Japanese.

Japanese-American screenwriter Iris Yamashita wrote the script, from a story by her and Oscar-winner Paul Haggis, who adapted ""Flags.""

Paramount will release the films domestically, while Warner Bros. International will distribute overseas. In Japan, ""Red Sun"" will be titled Letters from Iwo Jima.

""Red Sun"" revolves around the real-life Japanese General Tadamichi Kuribayashi, played by Watanabe, who battled American troops for 40 days on the small island of Iwo Jima.

Also starring in ""Red Sun"" are Japanese thesps Kazunari Ninomiya, Tsuyoshi Ihara, Ryo Kase and Shido Nakamura.

Along with Spielberg, producers are Eastwood and Robert Lorenz (Million Dollar Baby). Haggis is executive producing

Eastwood will lens most of ""Red Sun"" in Los Angeles, but has received permission to shoot exteriors on Iwo Jima.

Watanabe (Batman Begins, The Last Samurai) last appeared in Memoirs of a Geisha.

Variety"