A new teacher, Nishida, arrives at a school in a depopulated district with only one class. - Then, there was a principal at this school who was trying to get him to go to university through backdoor admission. - Nishida, who has a stronger sense of justice than anyone else, gets into a conflict with the principal and insists that he let her go to university on his own without relying on such backdoor methods. - First, Nishida uses his own anus as a subject in his class in order to make the students aware of the importance of learning. - We will carefully teach you how the anal works and reward those who do well. - After making peace with the principal and succeeding in expanding his anus, he tells her that he should never give up on anything through the most difficult public two-hole sex.