Ijô seiai kiroku: Harenchi (1969)

Starts with this skinny Asian chick—ribs showing, long black hair covering her face—lying face-down on a tatami mat, hands tied behind her back. The rope work looks tight, no slack, and she’s not going anywhere. Then the guy shows up, average build, slicked-back hair, and they get right into it. He flips her over and fucks her missionary-style, her legs wrapped around his waist like she’s holding on for dear life. The lighting’s dim but you still see everything—her small tits bouncing, his dick sliding in and out. No fluff, just straight-up rough sex with a bondage setup that actually looks like it hurts. Camera stays close, so you get all the details—her face when he pulls her hair, the way her body tenses up when he goes deep.