Shirobara gakuen: Soshite zen’in okasareta (1982)

Starts with this inked-up brunette—long wavy hair, tight body, tattoos running down her left arm and back—getting her neck kissed by some athletic white guy. She’s all over him, then flips face-down on the bed like she’s ready for whatever. Next cut jumps to a skinny Asian girl with straight black hair, sitting on a couch while the same dude goes down on her; she’s got that quiet, intense look like she’s about to lose it. They switch between the two girls, doggy style on the bed, then the brunette riding him reverse cowgirl so you get a clear shot of her ass bouncing. Camera’s tight on the action—close-ups of dick sliding in, faces when they cum. No fluff, just back-to-back fucking in a small room with clothes everywhere, like they didn’t even bother cleaning up first.