Ririko Nanase—a Special Magic Diplomat and a veteran magical warrior known as “Sweet Lip”—is ordered to conduct an undercover investigation at Proxim Academy by posing as a teacher.
Despite the unexpected nature of the mission, her life as a teacher was off to a smooth start, thanks in part to the assistance of Haruka Oshiro, a junior magical warrior attending the same academy… However, just at that moment, the academy is occupied by a surprise attack from demons led by the High Demon Dirac.
With students and faculty taken hostage, Ririko and Haruka find themselves completely helpless. In exchange for the safety of the hostages, they are subjected to a violent hell of pleasure.
Into this besieged academy, magical warriors from another world also begin to appear…