Chikan ramu-ramu densha (1986)

The girl’s lying on her back early on, one hand on her tit, eyes half-closed, wearing just a white bra. She’s got short black hair, slim frame, pale skin — looks like she’s prepping for what comes next. Cut to her on all fours, getting pounded from behind by a short-haired dude with a lean build. He’s going hard, slapping her ass, deep strokes you can hear in the audio. She switches to riding him, slow at first, then bouncing faster, leaning back so you see the full penetration. They were fully naked by then, no clothes on the bed, just her sweating, hair stuck to her neck. Later scene shows them at a dining table, both dressed, acting casual like nothing happened — probably right after the train scenario. Final shot is her alone again, eyes closed, face relaxed, possibly post-sex glow. The creampie leakage is visible once he pulls out, messy and real.