Musubu Mayumori is a first-year student in class 1-2 at Temarisawa High School, born on October 27th under the Scorpio sign and standing 156 centimeters tall. Her deep passion for singing, ignited in early childhood, fuels her aspiration to become a great vocalist. This dedication drove her meticulous search for the right music club; she evaluated both the light music club and the chorus club but found neither met her rigorous standards, ultimately leading her to the a cappella club.

Within the a cappella club, she holds the position of first chorus and approaches singing with intense seriousness. She constantly strives for personal improvement and demands equally high commitment from fellow members, a driven attitude and strong will that occasionally sparks friction due to her insistence on collective excellence. Her meticulous vocal care is evidenced by the throat spray she carries.

Often perceived as aloof and stern, with black hair and black eyes contributing to this impression, Musubu's personality is defined by unwavering focus and a refusal to compromise on her vocal ambitions.