In the hentai series 'Gakuen Shinshoku: XX of the Dead', a sudden zombie apocalypse engulfs an all-girls high school, trapping a group of terrified students. The series follows Mizuki, Aoi, and their friends as their desperate fight for survival devolves into a nightmare of sexual horror. These aren't ordinary zombies; they are driven by an insatiable lust, using grotesque, tentacle-like appendages to brutally rape and impregnate their victims. The 'shinshoku' or 'erosion' process is a central theme, as the girls are subjected to relentless gang-rapes, their minds and bodies broken and corrupted by the zombies' seed. Each episode escalates the depravity, showcasing graphic scenes of the schoolgirls being violently fucked, their resistance crumbling until they are reborn as mindless, drooling sexual slaves for the undead horde, eager to join the orgy and spread the erotic plague.