Mio Akiyama is one of the central characters and serves as the bassist, second vocalist, and primary lyricist for the light music club band Ho-kago Tea Time. She is a left-handed musician who plays a Fender Jazz Bass named Elizabeth and began playing bass in middle school after her childhood friend Ritsu suggested it. Mio originally intended to join the literature club but was pulled into the light music club by Ritsu, a decision that ultimately shapes her high school experience. She is a diligent and responsible student, consistently ranking among the top ten in her grade across all subjects, and she approaches her music with a technical and passionate mindset. Despite her serious and mature demeanor, Mio is deeply shy and sensitive, easily embarrassed by attention and prone to anxiety when placed in the spotlight. She dislikes being the center of attention and often tries to avoid taking lead vocal duties, preferring to sing only when necessary. Her shyness is compounded by a strong fear of horror, ghosts, blood, and other macabre topics, which can incapacitate her. Mio writes most of the band's songs, and her lyrics often reveal an unexpectedly cute and girlish side that contrasts with her usually composed exterior. She is warm-hearted and kind, especially toward the younger club member Azusa, with whom she develops a sisterly bond. Mio's closest relationship is with Ritsu, her childhood friend and the club's drummer, who frequently teases her and drags her into embarrassing situations, though they share a deep, affectionate camaraderie. She also acts as a grounding presence for her more carefree bandmates, often serving as the voice of reason and the one who pushes the group to practice and improve. Over the course of the series, Mio gradually overcomes some of her insecurities, grows more comfortable on stage, and learns to embrace her role in the band. She maintains her academic and musical discipline while becoming more open to new experiences, especially after moving on to university. Her notable abilities include advanced bass technique, songwriting, and strong vocal skills, which she demonstrates in performances of songs like Fuwa Fuwa Time and Pure Pure Heart.