Isao Egawa serves as a music teacher and composer at an elite school for aspiring musicians. He initially favors student Miki Koda, drawn by her family's wealth and social status, and grants her private tutoring. Gradually, however, Egawa recognizes Nozomi Mine's exceptional raw talent and dedication, shifting his focus to her development as a singer despite her impoverished background. This change occurs as Nozomi consistently demonstrates superior musical ability through hard work and passion, contrasting sharply with Miki's reliance on privilege over genuine effort.

Egawa guides students through the music industry's challenges, emphasizing perseverance and artistic integrity. He observes distinct approaches: Miki employs underhanded tactics and financial advantages to undermine Nozomi, while Nozomi depends on innate skill and relentless practice. Egawa acknowledges Nozomi's struggles, including financial hardship and bullying from Miki, remaining a critical yet supportive figure in her journey. His interactions highlight class disparities within the school, noting Miki's isolation despite her wealth against Nozomi's strong friendships forged through genuine kindness.

He functions as an impartial mentor who values true talent above social standing, ultimately fostering Nozomi's growth by providing opportunities to showcase her abilities. His guidance proves instrumental in helping her navigate professional obstacles like industry exploitation and rivalries. Egawa's character reflects the broader themes of meritocracy and resilience within competitive music education.