Ibu Himuro serves as the class president of RR Gakuen, a position that establishes her as a central figure of authority and discipline within the school's privileged environment. She is known by the epithet Oshare Bancho, which marks her as a stylish leader who commands respect from the student body, all of whom come from affluent backgrounds. Her physical appearance is characterized by her sleek black hair and a composed, elegant demeanor that underscores her authoritative presence. Personality-wise, she is presented as poised, gelassen (a German term suggesting calmness and composure), and responsible, fully embodying the duties expected of her role as iinchou, or class president. Regarding her motivations, her narrative focus is dedicated to upholding the high standards of her institution through unwavering dedication to leadership, with her primary task being the maintenance of order and the management of student affairs within RR Gakuen's opulent halls. The available information does not provide details on her background, her role in the specific story of "Second Collection," her key relationships with other characters, any personal development she may undergo, or any notable abilities she possesses beyond her leadership skills.