Kimajima-sensei was invited to the graduation party of the class she was the homeroom teacher for. Three days after the graduation ceremony, the class gathered at a bar run by the students' parents. This class reunion was orchestrated by a female student. Kimajima-sensei had started dating a male teacher she had admired. In revenge for such a trivial reason, the teacher was raped by the whole class. "Everyone, rape this woman!" The despicable mastermind turned the graduation party into a creampie gangbang party...