Ryou Seibai! ~Gakuen Bishoujo Seisai Hiroku~

Private Kibitsu Academy is a prestigious school brimming with talented, beautiful female students, but beneath its shining surface lies a grim reality controlled by the autonomous Gakuseikai student council. The protagonist, Hinase Kyouichirou, enjoys a peaceful life with his sister-in-law and teacher Saki, until her brutal assault by council members leaves her mentally shattered. Consumed by helplessness, Kyouichirou is approached by school nurse Yamiko Shiroyuki, who offers him a role in her auditing team to dismantle the corrupt Gakuseikai. Swearing to restore justice, he joins the fight.