A good friend of Kanna. She has feelings for Tetsurō, and sometimes her thoughts seem to innocently go in a sexual direction. Every time she is shown at home she is nude; she also sleeps in the nude (even when sleeping with Kanna) and dislikes wearing underwear. When confronted about this she says that her family are nudists, and that she hides this fact from everyone due to her embarrassment over her family's unusual lifestyle. She is shown to have quite sensitive skin as well, which complicates her other issues. She's for the most part sweet and innocent. She has had very long hair, but after confessing her feelings to Tetsurō, she cut her hair short. Despite being the most gentle and soft spoken of the group, Mio has shown that after her confession to Tetsurō and haircut, she has grown as an individual. She offers words of advice to Tetsurō on how to deal with his feelings for Kanna despite her own feelings towards him. She has shown that, while she may be timid at times, Mio is not only observant and selfless (a trait shared by Kanna and Tetsurō as well), out of her friends she is the most well rounded and has been described as "strong" by Tetsurō himself. After Tetsurō confesses his love for Kanna only to be rejected, Mio comforts and once again, offers kind words to him. While eluding the Federation, Tetsurō asks Mio on a date to the movies.