Mathematics teacher Miyuki Yonehara is getting into an illicit relationship with her student, Koichi, who is also the student council president. Then she finds out that Koichi has had an affair with student teacher Himeko Ayatsuji. Her forbidden feelings towards her student, her pride as a homeroom teacher. In the midst of a battle between women over one male student, Miyuki becomes more and more crazy, depraved and corrupted day by day...