Hiroto Kanazawa is a music teacher at Seiso Academy, primarily responsible for overseeing the school’s music competition. He is a tall man, standing 183 centimeters, with distinctive purple hair and yellow eyes, and is often seen with a casual, somewhat unkempt appearance that includes stubble and a lit cigarette. Despite being in his early thirties, he carries himself with a lazy and apathetic demeanor, often appearing indifferent to his duties and irritated by troublesome tasks.

Behind this lackadaisical exterior lies a much more complex history. In his youth, Kanazawa was a famous and promising tenor, having built a successful career as an opera singer in Europe. However, a personal tragedy led to his downfall. After a romantic relationship ended painfully, he turned to heavy drinking and smoking, habits that severely damaged his vocal cords and made it impossible for him to continue performing. Forced to abandon his dream, he returned to Japan and accepted a teaching position, viewing it more as a practical necessity than a calling.

In his role at Seiso Academy, Kanazawa often appears to be the quintessential slacker. He is known to be careless, frequently tries to avoid work, and is a chain smoker who ignores criticism about the habit. However, when a student genuinely requires guidance or is struggling with a problem, he will provide sharp and practical advice, revealing a hidden sense of responsibility. He is generally well-liked and popular with the student body because he is approachable and easy to talk to, lacking the strict formality of other teachers. He has a close, informal relationship with the students, with characters like Kazuki Hihara affectionately calling him Kanayan, while the absent-minded Keiichi Shimizu can never seem to remember his name correctly.

Despite his reluctance to engage with the music competition he supervises, the event becomes a turning point for him. Watching his students dedicate themselves to their music and struggle with their own passion gradually inspires him. He begins to take a more active interest in their development, and this exposure to their enthusiasm helps him contemplate his own past and the possibility of starting over. Even in his defeated state, he retains notable abilities, possessing deep and profound knowledge of music and singing that he can call upon when necessary. When not at school, his hobbies include fishing, cooking, and watching baseball, and he is known to have a soft spot for feeding the stray cats that live on the school grounds.