Miharu Nijino is a supporting character who serves as the adviser to Kaoruko Moeta, Ruki Irokawa, and Tsubasa Katsuki at Suidoshi High School. She is also a Japanese history teacher known for maintaining a strict and serious demeanor in the classroom. Beneath this professional exterior, however, she possesses a childlike and nerdy personality, which is a remnant of her own past as a manga artist. During her own high school years, Miharu was an active member of her school's manga club and worked as a mangaka, but she eventually gave up that career path in order to become a teacher. Despite leaving professional manga behind, she still enjoys drawing in her private time and uses the pen name nijiko to post her own comics and illustrations online. Her motivations are rooted in a blend of professional duty and genuine care for her students' growth. Initially, she comes across as strict and aggressive toward the main girls, often scolding them for being late, but this tough exterior masks a gentle-hearted nature that is easily excited by her hobbies. She deeply treasures the friendships she formed in high school, a sentiment that informs her role as an adviser. In the story, Miharu acts as a bridge between the girls' everyday school lives and their aspirations as budding manga artists, offering guidance while also quietly supporting their creative efforts from behind the scenes. Her key relationships are primarily with Kaoruko, Ruki, and Tsubasa, whom she advises and observes as they navigate both school and their manga careers. Over the course of the series, Miharu's character develops through small moments where her hidden enthusiasm and warmth break through her strict facade, revealing a more approachable and relatable figure. A notable ability is her capacity to switch between her stern teacher persona and her private, nerdy self, reflecting a duality that makes her both a figure of authority and a former peer in the creative field she once pursued.