[Saki Chizuru] Kokan Shinrei Spot! Kagaku de Kimochi ii Jorei!? (2D Comic Magazine Futanari Kikaikan Seieki o Shiboritsukusu Kikai Zeme Jigoku!! Vol. 2)

A bespectacled researcher with a massive bust straps a bound, buxom futanari subject into a high-tech contraption of pistons, cylinders, and clear tubes, eager to test her homemade 'ejaculation equipment.' As the machines whir and squeeze, the captive's shaft is relentlessly stimulated while the scientist watches in clinical fascination, taking notes on 'slimy, tight' sensations far better than the real thing. The relentless mechanical torment pushes the trembling test subject to the very limit, leaving her writhing, sweating, and utterly at the mercy of her unhinged inventor's experiments.