Inoue, Sumiko

井上澄子

She serves as the head of the school's "Disciplinary Committee" and possesses an uptight personality, taking her duty of enforcing school rules very seriously alongside Kyouko (her enforcer) and Masako (her secretary).
It was later revealed that she is Shibaki's childhood friend.
It is hinted that despite her uptight attitude, she actually wishes to be victimized by Shibaki's perversion. Unfortunately, he remains largely oblivious to this.