Mio Akiyama is the main protagonist of K-ON! She is the bassist and also a lead vocalist alongside Yui of Houkago Tea Time. she is shy and very delicate and is easily embarrassed, and she reluctantly joined the Light Music Club due to Ritsu asking her to due to being on the verge of disbanding, her Bass which she nicknamed "Elizabass" curtesy of Yui. She has good experience playing her bass and good experience of singing too. However, she was traumatised in her first live concert due to an incident where she tripped over a cord and fell flat on her face and revealing her panties by accident. She, along with the rest of the Light Music Club, also appeared in Hollywood World and Full Moon's Full Pokemon Journey.