Kunoichi ninpô-chô IV: Chûshingura hishô (1994)

One of the girls has a sleek black kimono that gets slowly peeled off in a dim red-lit bedroom scene — she’s curvy, not the typical petite ninja type, and it stands out. They start with light touching behind a painted screen, fingers tracing necks and thighs, then move into full-on girl-on-girl action on a futon. The camera stays close during oral, really focusing on how deep one of them goes, no hiding the thrusting. Outdoors, there’s some spy-like tension between two men in a garden but nothing explicit — all the heat’s inside with the women. The whole thing leans into the ninja theme with traditional clothes and architecture but delivers straightforward porn scenes without gimmicks. Lighting plays a big role — warm indoors, cool and blue outside — gives it a moody, cinematic look even during hardcore sex.