Mio is very reserved and bashful by nature. She is private and soft-spoken, even amongst close friends, and seems to enjoy time alone, which she often dedicates to songwriting. She has been socially anxious and self-conscious since she was small, hence falling prey to a young Ritsu's teasing, and typically retreated into the sanctuary of her books. She struggles to interact with strangers, has few friends outside the Light Music Club (despite her popularity), and is strikingly sensitive.