Mio Akiyama is one of the main characters of the K-On! anime and manga.
Mio is the mature but scaredy-cat bassist, and second vocalist of the band, After School Tea Time.
In the AWA fics, Mio is a student at the AWA Academy and is a part of Class 2.
In the XP4 fics, Mio is a student at the Vanguard Academy.
Mio stands at 5'3", being the tallest in the group and has straight, long, black hair and gray-blue eyes. As shown in episode 4 of season 1, she is also quite a bit more busty than the others (except Mugi), much to Yui and Ritsu's dismay, and later Azusa's as well.
Pants over skirts. In summertime, she likes to wear sleeveless clothes, such as tank tops.
Like all Sakuragaoka High School students, Mio wears a school uniform. The Sakuragaoka uniform consists of a navy blue blazer, a solid white buttoned shirt (under the blazer), a colored ribbon (different colors for different student years, Mio's year is light blue), a light steel blue skirt, stockings or socks (Mio's are black), and maroon shoes. The summer uniform replaces the blazer with a beige waistcoat. Additionally, the subject physical education requires a tracksuit (sport jacket with long pants, colored again depending on the year group) with white striped brims, a white shirt with colored endings (again colored regarding the year group) for the summer semester and white sports shoes.
Mio is the bass player of the Light Music Club. Even though she acts mature, calm and collected most of the time, she freaks out from things she's afraid of, are gross, or pertain to gore. She is a tsundere towards Ritsu often, due to Ritsu's immaturity. Because of her extreme shyness, she chose the bass over the more conspicuous guitar. She is so delicate that merely imagining herself being the center of attention almost makes her faint, but she still plays the bass quite well. She is kind and warm with others, caring about her friends and knowing they are important to her.
Although she is not altogether uninterested in joining a band outside school, the time she spends with the Light Music Club members is the time she enjoys the most, so she has completely devoted herself to the club, and during the school festival performance in the fall of her first high school year, she acted as lead vocalist instead of Yui, who had lost her voice. At the time it seemed like Mio might have overcome her stage fright, but after the performance ended, she tripped over a cord and fell, exposing her panties, and was traumatized anew.
- Mio is the first character from K-on! to be introduced in the AWA fics.
- In the AWA fics, for some unknown reasons, Mio gains a crush on Killua Zaoldyck from Hunter X Hunter.
- Her bass guitar is a left-handed Fender Japan '62 Reissue Jazz Bass in 3-Tone Sunburst, and she usually plays with a pick. It gets named Elizabeth by Yui. In Japanese, since "bass" and "Beth" are both pronounced as "besu", this results in a pun where the name can be interpreted as "Elizabass". Initially Mio dislikes this name, but comes to like and accept over time. She uses D'Addario EXL160 strings on it, though they are incorrectly shown as EXL160M strings, even though her bass is not a medium-scale. There is a medium-scale version of Mio's bass, but it is only made as a right-handed verison. Fender Japan's page for the JB62/LH.
- Mio is left-handed.
- Her surname is taken from former P-Model bassist and keyboardist Katsuhiko Akiyama.
- Mio seems to be a fan of Lomography, as she is often seen with a camera strongly resembling the Lomo LC-A during Ho-kago Tea Time's first summer trip.
- Megumi Sokabe, the former president of the student council and also former president of the Mio Akiyama Fan club, asked her for an autograph signed "Mio-tan" after being amazed by Ho-kago Tea Time's surprise private concert for her.
- Mio tends to pick desserts with strawberries the most often.
- Mio has the largest hands out of all the members of HTT, which is very useful for a bassist.
- Mio is known to write the kanji for person three times on her palm and then pretend to eat it when she gets nervous.