The narrative takes place at Seitei Gakuen, an elite private academy in Tokyo that educates students from kindergarten through college. Minami Yuuri, a new female teacher, begins her second year at the school, transitioning from middle school instruction to the role she had pursued: teaching grammar to high schoolers. However, she is placed in class 3-E. Known as "Class X," this group of seniors has a notorious reputation for lacking study skills; rumors claim all their former teachers retired due to ulcers or neurosis. Minami must attempt to connect with these students, including the six leaders of the "B6" (Baka 6), and guide them toward college admission.