The hentai series 'Shikiyoku Infinite' chronicles the sexual degradation of two sisters, the student council president Sayaka and her younger sibling Mao, after they install a cursed application. This app, controlled by a lust demon, blackmails them into performing increasingly perverse and public sexual acts. The series follows their horrific descent from innocence into depravity, starting with forced public masturbation and flashing, quickly escalating to brutal gangbangs where their bodies are used indiscriminately by monstrous men. Each episode pushes their boundaries further, forcing them to deepthroat countless cocks, have their faces plastered in semen, and endure relentless anal and vaginal violations. The narrative arc focuses on their complete psychological collapse, showing them being mind-broken by the constant humiliation and overwhelming forced orgasms, eventually transforming them from terrified victims into cum-addicted, broken sex slaves who crave the very debauchery that destroyed them.