Sara Tadeshina is sent by a high priest to St. Moses Academy as an undercover substitute teacher to start an investigation. Given only cryptic clues to guide her quest, she tries does her best to uncover the truths behind a rising mystery.
Meanwhile, Mayu, a young student, is dragged into Mija’s realm. Under Mija’s spell, she learns the pleasures of the flesh. Unable to contain herself, she willingly returns to Mija’s lascivious den for more and more.
But Kotaro, who is secretly nursing feelings for Mayu, notices the disturbing change in her behaviour. He bravely follows Mayu into Mija’s den to try to save his love, but will Sara be in time to save both Mayu and Kotaro? Will she be able to defeat Mija and her converts?