After school nightmare 1

You have just awakened to find your darkest secret revealed to a group of people who would do anything to destroy you: your classmates! That's what happens to Ichijo Mashiro, whose elite school education turns into the most horrifying experience of his life when he's enlisted to participate in an after-hours class. The only way for Mashiro to graduate is to enter into a nightmare world where his body and soul are put at the mercy of his worst kind of enemies. Can Mashiro keep the life-long secret that he is not truly a he nor entirely a she, or will he finally be outted in the most humiliating way possible?.