Dan Oniroku bara no nikutai (1978)

One of the women has a sharp black bob, the other long straight black hair — both are slim and fully into it. They start off talking in a living room, then move to a balcony, but the real action kicks off in the bedroom. The guy eats out the one with the bob while she grinds against his face, close-up shots showing every wet slide. Later, they switch to missionary with the long-haired girl, her legs high, taking deep strokes. There’s an alleyway meet-up and a bar scene with a gramophone in the background, but the sex is the focus — raw, well-lit, no fluff. Camera stays tight during penetration, pulls back just enough during transitions to show setting.