Abandon 100 Nuki Shinai To Derarenai Fushigi Na Kyoushitsu

The students find themselves locked inside their school with a mysterious being called “The Ruler” and forced to participate in a dark sex game at the behest of mysterious forces. The story has a battle royale element, in which players use their “game skills” to try to make each other come, for example by turning into a demon, releasing depraved tentacles or using futanari torture. The host of the game is a certain “Ruler” who watches the beautiful girls while they bring themselves to orgasm in humiliating games using depraved techniques and body modifications.