As the Executive Committee Treasurer of the high school Student Council, Kirika Hijiribashi takes charge of an impressive budget worth 800 million yen. In addition to her responsibilities, she holds the unique position of Student Council Detective and possesses the ability to uncover extraordinary solutions to puzzling cases. When Hikage Makimura, a new transfer student, unwittingly becomes a member of the Student Council, he is unexpectedly appointed as her assistant.