You can't keep a good girl down.
This dramatic poster was made for Nikutai no mon, aka Gate of Flesh, a movie based on a 1947 novel by Japanese author Taijirô Tamura. The book has been filmed five times. The most famous version was made in 1968 with Jo Shishido and Yumiko Nogawa earning acclaim for their lead roles in what was a serious and artistic film, but the above promo is for the 1977 roman porno version starring Reiko Kayama, Izumi Shima, and Junko Miyahsita. Needless to say, the two films diverge rather sharply. However, we need to point out, as we do periodically, that roman porno isn't porno—it's softcore. The “roman” in roman porno is short for “romantic,” and though the movies aren't typically romantic in the normal sense, they aren't explicit. Such depictions were illegal in Japan back then, and remain so today (though filmmakers use pixilation of sexual organs to skirt the law).
When the novel Nikutai no mon appeared in 1947 a different censorship regime existed called the Civil Censorship Detachment, which was under the authority of the Supreme Commander for the Allied Powers, aka Douglas MacArthur. Under SCAP CCD censorship, explicit accounts of fraternization between Japanese and whites were forbidden, as were detailed accounts of the atomic bombings, or anything that could generate distrust toward the American occupiers. Most Japanese authors obeyed. A few wrote obliquely about the forbidden subjects. And a very few broke the rules entirely to describe war horrors—e.g. flashburned nuclear victims walking naked and blind amongst the ruins, their hairless bodies so swollen their sex could not be determined. Tamura's novel falls in the middle. It tells the story of a group of Japanese women trying to survive in the rubble of Tokyo via prostitution.
Where the 1968 movie stuck pretty close to Tamura's fiction, the roman porno focuses more on the sexploitation angle, though it keeps the action set in 1947. A criminal syndicate known as Black Rose provides Japanese girls as prostitutes to the American military, and any who resist the various examinations, training, and indignities are punished with torture and death. When Reiko Kayama arrives on the scene, she eventually inspires the others to follow her as she leads a revolt against her enslavers. You get sex, girlfights, killings, and blood. If you're looking for standard roman porno fare—with perhaps a bit more visual piazazz than usual thanks to director Shôgorô Nishimura and cinematographer Yoshihiro Yamazaki—you've picked the right film. Nikutai no mon premiered in Japan today in 1977.