Hiromi Hosokawa is a supporting character in the series, serving as a fellow teacher at the all-boys private high school where the protagonist works. Her exact family background is not detailed extensively, but she is presented as a career-oriented educator who is well-established within the school’s faculty. She often represents the traditional, rule-abiding side of the academic institution.

In terms of personality, Hiromi is generally serious, proper, and somewhat formal. She initially holds a strong skepticism toward unorthodox teaching methods and is easily frustrated by colleagues who do not follow standard procedures or uphold the school’s rigid reputation. She can come across as prideful and competitive, particularly regarding her status as a teacher. However, beneath this exterior, she is not malicious; rather, she is genuinely dedicated to maintaining what she believes is correct for the students and the school’s image. Her motivations stem from a desire for professional validation and a need to see the education system function by its established rules. She wants to prove that traditional discipline and academic rigor are the correct paths for students.

Her key role in the story is often that of an antagonist or foil to the protagonist. Hiromi questions the protagonist’s unconventional methods, which often involve street smarts and personal connections rather than hierarchy and textbooks. She frequently serves as a voice of the faculty’s concerns, highlighting the protagonist’s clashes with the school’s administration. Regarding key relationships, she is close to other faculty members who share her traditional views, but her most significant dynamic is with the main character. This relationship evolves from one of rivalry and distrust to a begrudging mutual respect as she witnesses the protagonist’s effectiveness and genuine care for the students. Her relationship with the students is initially strict, but she softens as the narrative progresses.

Throughout her development, Hiromi undergoes a notable shift. She starts as a primary critic of the protagonist’s chaotic class, but repeated exposure to positive results forces her to reconsider her rigid stance. She learns to value results and heart over strict adherence to rules. While she rarely abandons her professional demeanor, she becomes a more supportive ally, occasionally covering for the protagonist or offering assistance when the situation truly requires it. Her notable abilities include a thorough knowledge of the school’s policies and a strong command of standard academic subjects, which makes her an efficient administrator. She is also perceptive, capable of noticing when students are acting out, even if she initially fails to understand the root cause. Ultimately, Hiromi represents the bridge between institutional tradition and the new generation of teaching.