The protagonist of the series. A self-proclaimed "below average" girl who likes playing shoot-em-ups and Western games, although her commute to school is far less mundane.
- Badass Normal: Sometimes intentional, sometimes not.
- Brick Joke: Chio expresses a desire for someone to confess to her standing on top of a pipe. Andou more or less accomplishes this in Chapter 33.
- Country Matters: Chio receives a message while playing a game that turns out to be this.
- Gamer Chick: She's a hardcore gamer, with a particular thing for stealth games.
- The Glasses Gotta Go: Subverted when Manana thinks removing Chio's glasses will reveal a more beautiful side to her, only to find out Chio just looks as plain as usual (if not plainer).
- I Know Mortal Kombat: Her knowledge of stealth games inspires her to use their techniques in real life. She turns out to be pretty good, resulting in many of her badass moments. Deconstructed in that she's only able to do that because she actually is very athletic (and even then it's often quite difficult), but tries to hide it so not to attract any attention to herself.
- Meganekko: She wears a pair of rectangular glasses, giving her a cute, nerdy look.
Manana is Chio's best friend who has been with her since elementary school. Despite their close friendship, the two will occasionally try to backstab each other.
Voiced by: Kaede Hondo
(Japanese), Kristin Sutton (English)
Yuki is Chio's classmate who is a sports ace. She is very polite and often oblivious to how people see her.
Momo is a member of the public morals committee at Chio's school who has a crush on her teacher, Gotō.
Madoka is a senior student at Chio's school who is captain of the Kabaddi Club. She has a strong passion for kabaddi, which she ultimately comes to realize is not based in the sport itself, but rather for it being the perfect excuse to grope other girls.
Gotō is a teacher at Chio's school who always waits at the school gates as students come in every morning. While stern, he deeply cares for his students and greatly enjoys his job.
Mayuta is a former biker gang leader who is tricked by Chio into quitting his gang and now seeks to earn an honest living as a convenience store clerk. He has a crush on Chio and often goes to absurd lengths to impress her.
- Big Brother Instinct: Andou comes to Chiharu's defense against Manana while out cold in chapter 23/episode 10.
Chiharu is Mayuta's younger sister, who has a bad habit of trying to poke other people's bottoms. She loves her older brother dearly and is driven to find the woman who made him quit his gang.