Oshioki: Gakuen Reijou Kousei Keikaku(2011)

Oshioki: Gakuen Reijou Kousei Keikaku is an anime series following Shimohei Joutarou, a new staff member who arrives at school before the academic year begins. On his first day, he uncovers secrets held by students Mitsuki and Minami, then learns of Mahiru's sudden academic improvement—a development linked to suspicious dealings by her sister, Classics teacher Kuji Hinako. As Joutarou pieces together evidence of Hinako's behind-the-scenes manipulation, he takes on the responsibility of disciplining and rehabilitating the rule-breaking students caught in her web. The series explores themes of institutional corruption and redemption within a school setting.