Students find themselves trapped in the enclosed space of their school with a mysterious creature called "Ruler" and forced to engage in a dark sexual game at the behest of mysterious forces.There is a battle royale element to the story, with players using their "game powers" to force themselves to cum by, for example, turning into a demon, releasing depraved tentacles or applying Futanari torture.The game's host is a "ruler" who watches beautiful girls as they bring themselves to orgasm in humiliating games using depraved techniques and body modifications.