Ore ga Kousoku! Nakadashi Igai wa Kousoku Ihan!!! ~Joshikousei Zen'in Nakadashi Kanzen Seiatsu Keikaku~

Hiriya Seita attends a high school that has two departments: Department of Athletics and Department of Cultural Studies. He was in the Athletics department at the beginning but due to an unfortunate accident, he was forced to transfer into the Cultural Studies department. However, the fact that he always had trouble with women did not help since the entire department consisted of only females! One day, when everyone is preparing for the school festival, he discovers another student breaking school rules in his online network. Vehemently confronted by the student, Hiriya uses her school rule violation as blackmail and forces her to do what he wants. In the wake of this incident, Hiriya ultimately realizes that even girls will do wrong if they are given the chance. As a result, he formulates a plan to use his network to blackmail the students around him by uncovering their wrongdoings. "I'll crack down on the entire female student body by making my own school rules!" Thus, this was how Hiriya's "Full-scale Female Student body Creampie Domination plan" started. [Loosely translated from Getchu]