Satomi Niiyama, a woodwind instructor recruited by Noboru Taki, assists the Kitauji High School Concert Band in competition preparation with specialized focus on woodwind sections. Proficient in flute and all woodwind instruments, she carries herself with gentle elegance—long, softly curled brown hair, neat makeup, and pastel attire like pink cardigans and white chiffon skirts, accented by pearl earrings. This refined presentation contrasts sharply with her college days of T-shirts, jeans, sneakers, and ponytails.

Her background includes music college, where she was one year junior to Noboru Taki and Masahiro Hashimoto, forging close friendships in their orchestra circle. Initially viewing Taki as grumpy and strict, she later developed mutual professional respect with him. She deeply admired Taki Chihiro, Taki’s late wife, considering her an older sister figure and declaring she "would do anything" for Chihiro’s happiness while openly preferring her over Taki. Chihiro’s death profoundly influenced her, inspiring her elegant style as tribute to her late mentor. Post-college, she married and pursued a professional flutist career.

Niiyama’s personality merges warm approachability with rigorous standards. She smiles gently, often covering her mouth, and exudes a mysterious yet comforting presence. During rehearsals, however, she matches Taki and Hashimoto’s strictness, demanding perfection through relentless practice. She emphasizes self-discovery in music, urging students to "enjoy it more" rather than treat performance as duty, and fosters emotional connections to instruments—advising Mizore Yoroizuka to "love your oboe."

Her teaching spans foundational techniques to advanced expression, employing group sessions, individual coaching, and connections to external music professionals. She participates in critical events: summer training camps, regional competitions, and national contests across multiple years. In Kumiko Oumae’s first year, she attends summer camp, inadvertently sparking rumors about being Taki’s girlfriend until Hashimoto clarifies her married status. Later, she apologizes to Mizore for underestimating her potential, encouraging her to "have some fun" with solos.

During Kumiko’s second year, Niiyama identifies Mizore’s talent, recommends her for music college, and guides her audition preparation while maintaining reserved distance from Nozomi Kasaki, who sought similar mentorship. Her most impactful guidance occurs during rehearsals for "Liz and the Blue Bird," where she coaches Mizore (oboe) and Nozomi (flute) on interpreting the piece’s emotional core through the folktale’s themes of separation and mutual understanding. Challenging Mizore to explore character emotions catalyzes breakthroughs in musical expression and personal growth.

By Kumiko’s third year, Niiyama supports the band through Kansai regionals and nationals. She observes audition tensions and diminished morale while concentrating on technical coaching. At nationals, she witnesses Kitauji’s gold medal victory, visibly moved to tears as Taki’s long-term goal is realized.

Her faculty relationships include collegial respect for Michie Matsumoto, whom she consults on daily matters, and collaborative professionalism with Hashimoto, whose teaching style she admires. With Taki, she maintains polite formality—addressing him as "Taki-sensei"—and occasionally teases him without romantic intent.