Honoka is a second year high school student and the founder of μ's. Her key characteristics are that she is always seen with a smile on her face and that she is full of energy. Whimsy and intuition dictate many of her choices, but once she decides on something, she races toward her goal without any hesitation. Even if things look grim, she overcomes such times with super positive thinking. She is the engine that drives μ's forward.

Eli is a third year high school student. She is a quarter Russian. She is clear-headed, has unparalleled physical flexibility, and can do almost everything at an above-average level. Even at school, she is very popular, and is admired for having a strong sense of responsibility.

Kotori is a second year high school student and Honoka's very first friend. These childhood friends have been together since kindergarten. In direct contrast with Honoka, she has a soft and quiet demeanor befitting of her honors student status. While she may be quiet, she is a strong and confident girl.

Umi is a second year high school student. She was brought up in the household of a dance school headmaster, which has helped her to become a graceful girl with a refined air. She has practiced archery since childhood and has flawless etiquette. She is the type of girl who is hard on those around her, but is especially hard on herself. She does not like doing anything remotely criminal, and abhors laziness. Honoka and Kotori are her childhood friends.

Rin is a first year high school student who is quite athletic and optimistic. She would rather take action and keep moving instead of sit and think.She finds joy in helping and looking after others, especially her good friend, Hanayo. No matter what anyone says, she always gives practice her all.

Maki is a first year high school student whose parents run a large, successful hospital. She is known among her peers as being an outstanding singer who is also rather adept at playing the piano. She is high-handed to the point of arrogance and has difficulty expressing her feelings. She is quite courageous, never hesitating to incite an argument, even with her upperclassmen. Even so, she has a side that she keeps hidden as best she can--she gets lonely very easily.

Nozomi is a third year high school student. In direct contrast to Eli, she has an easygoing personality and has a unique manner of speaking, due to her relaxed-sounding Kansai dialect. She and Eli make a good combination, with Nozomi acting as Eli's foil. She has a motherly heart, leading others to think that she is the most mature of the members. Although she seems nonchalant, she can be surprisingly conniving.

A first year high school student, Hanayo struggles more than others to stand out in class due to her meek personality. She lacks any traces of self-confidence and tends to give up on everything she attempts. She adores ?'s, so she decides to join the school idol group along with her reluctant friends, Rin and Maki. She gets along well with Rin, and they quickly grow inseparable. She is perfectly happy eating a bowl of nothing but white rice.

Nico is a third year high school student. She works hard to become an idol day in and day out--a true idol otaku. As their senior in school idol experience, she often bosses Honoka and the others around. While she may talk big, she does mess up a lot, making her an unexpectedly klutzy girl. Her catchphrase is "Nico-Nico-Ni!"

The second-year student at Uranohoshi Girls' High School who launched Aqours. The youngest of three sisters, she comes from a ryokan-owning family and is proud of their open-air, ocean-view bath. Sociable and rarely gives in easily. Her positive, can-do attitude gradually begins to affect everyone around her.

A second-year student who joined Chika's class after moving from Akihabara, Tokyo. She may look calm and mature, but she often flies into a panic, jumping to conclusions and making mistakes.

A third-year student who is breezily mature and she rarely sweats the details and usually maintains a calm, cool demeanor.

A third-year student who leads the student council. From an old fishing family whose name is well-known around the area. Prideful and perfectionistic in her ways, she can't abide it when things are done sloppily or incorrectly.

A second-year classmate of Chika's. Good enough at the high dive to qualify for the national team. She tends to take action without thinking matters over first. Her father captains a ferry, and she'd like to have his job someday.

A first-year student who likes the "little devil" look and proclaims herself to be "Yohane, the fallen angel". Born in the urban side of Numazu city, she's bright, self-assured, smart, and thoughtful. She's also cursed by extreme bad luck, running into all kinds of unforeseen trouble wherever she goes.

A first-year student, the daughter of a family who's run a nearby temple for generations. A fan of reading, she has a deep fondness for Japanese literature. She's also a gifted singer, earning her a spot in a choir and gentle and caring for those around her.

A third-year student. Her mother is Japanese, while her father is Italian-American and manages a hotel chain. Cheerful in personality, she often prefers to work by herself. Always keeps her chin up when faced with hardship and ready to try her hand at anything.

A first-year student who's almost always nearby her good friend Hanamaru. Fearful and tends to cry a lot, but still has a tough interior, forged by her role as a girl in a rich, well-known family. Always looked up to pop idols. Needlework is the only thing she's really great at.