Ashiya reijô: Ikenie (1986)

The woman has long dark hair and a yellow tropical-print dress that gets taken off later — you see her in close-up first, just the dress in low light, then later fully naked on the beach. She’s slim, small tits, and gets into it hard — on top of the guy, grinding slow at first, then picking up pace. The guy is short black hair, slim build, lies back in the sand while she rides, then they switch to doggy near the flames. Earlier, they’re in a kitchen, sitting at a table with wine, not saying much, just eating or pretending to — the vibe is quiet, not playful or cheesy. The beach scenes are the real focus: wide shots show the whole bonfire setup, you can see their legs and arms moving, the way the fire lights their skin. No faces are super clear in the dark, but the camera stays wide most of the time, no cuts to fake moaning or close-ups that don’t match. The sex looks real, no faking positions or awkward angles.