Letters from Iwo Jima
From The Internet Movie Plane Database
Ken Watanabe (General Kuribayashi
Kazunari Ninomiya (Saigo)
Tsuyoshi Ihara (Baron Nishi)
The Imperial Japanese Army Air Service did not operate the Beechcraft Model 18, I presume this aircraft is representing a similar aircraft type the Kawasaki Ki-56 flown by the Imperial Japanese Army Air Service during this era.