Okamoto belonged to what one colleague called "the generation where most of them got killed": the leagues of university graduates who were drafted into and sacrificed to the last years of Japan's war in the South Pacific. Okamoto was drafted during the very worst of it, in 1943, but almost alone among his colleagues managed to survive. The experience helped shape his outlook on the nature of human conflict in general, and the Japanese war in particular: among his earliest successes (which led to a series) was Dokuritsugu Gurentai (1959), an acerbic story of island-bound soldiers that helped make Okamoto's reputation. Okamoto also made a name for himself as a director of equally cynical gangster pictures at Toho, including Boss of the Underworld (1959) and The Age of Assassins (1967). Kihachi Okamoto began his filmic training in 1945 under such estimable teachers as directors Mikio Naruse, Senkichi Taniguchi. and Ishiro Honda.