Kekkō Kamen (けっこう仮面, Kekkō Kamen) is an adult rated manga and anime series from Japanese creator Go Nagai. The series is about the misadventures of a student named Takahashi Mayumi who attends a boarding school called "Toenail of Satan's Spartan Institute of Higher Education" that is run by sexual predators. The teachers are constantly looking for ways to torture or humiliate the students, and from this the teachers derive sexual satisfaction. Takahashi's only protection is from a mysterious figure known as Kekkō Kamen.