Tsugi wa Anata ga Yarareru Ban desu.

A normal day at high school comes to an abrupt end when a group of armed men invade the school. The students are held hostage by the gunmen now in control of the school. A mad orgy of sex and death will unfold. What awaits them after that? An erotic suspense horror story begins. (Source: Dengeki Daioh, translated)