Busou Shoujo Machiavellianism centers on Fudou Nomura, a boy expelled from his previous school who is sent to Aichi Coexistence Private Academy, an institution that looks ordinary from the outside but is governed by a harsh and unusual order. Inside the academy, the female students carry weapons and enforce discipline through strength, while the powerful group known as the Supreme Five Swords keeps the campus under control and pushes male students to crossdress and either accept life inside the female student body or leave the school altogether.
On his first day, Fudou clashes with Rin Onigawara, one of the Supreme Five Swords, after she orders him to obey the dress code or quit the academy. He refuses, and what begins as a simple confrontation quickly turns into a fierce fight that shocks the students around them. Fudou’s combat ability soon attracts the attention of the other Swords as well, placing him at the center of a school environment where every hallway encounter can become a challenge of pride, strength, and survival. As the tension between the male transfer student and the academy’s armed enforcers escalates, the series builds a constant struggle over authority, identity, and who gets to define the rules of the campus.