Japan has now become one of the world's most erotic adult powers. Sex becomes a big culture for the Japanese and is actively incorporated into school. From lectures to pratical lessons, every sexual knowledge is taught widely. This story takes place at a private christian girls school, where there is a class that collects students who are treated as problem children. The protagonist is here to teach them sexual knowledge. As their teacher, he will engage in various ecchi situations for the sake of teaching.