Kodaka Hasegawa (羽瀬川 小鷹 Hasegawa Kodaka)
Voiced by: Ryohei Kimura (Japanese), Jerry Jewell (English)
The viewpoint character of the light novels, Kodoka is a transfer student who has been unable to make friends in his first month at St. Chronica's. He and Yozora Mikazuki start the Neighbor's Club with the purpose of learning how to make friends and how to act in social situations. Of the members of the Neighbor's Club, he is the most gentle, balanced and socially competent in personality; but his unusual spotty-blond hair color, inherited from his late English mother, leads classmates to assume he is a violent and abusive delinquent and to spread defamatory rumors about him. Because of his reputation, Kodaka has become accustomed to conflicts and having to defend himself.
Kodoka's childhood has been characterized by frequent moves. As a result, he has few memories related to home life, and no friends to speak of besides a single childhood friend whose name eludes him. After being away from the area for ten years, he moves back with his younger sister, Kobato, while his father continues work as an archeologist in the United States. He later realizes that his childhood friend is none other than Yozora, although Yozora has known since the beginning.
In Volume 8 of the light novel, Kodaka asks Rika to be his friend. This is the first time Kodaka has made a true friend in a decade since Yozora.

Yozora Mikazuki (三日月 夜空 Mikazuki Yozora)
Voiced by: Marina Inoue (Japanese), Whitney Rodgers (English)
A cruel and selfish black-haired girl who says she understands and respects bullying but resents being called a bully herself; her difficult personality drives away anyone who might wish to make friends with her before she meets Kodaka. She is physically abusive towards, and often argues with, Sena and manipulative towards Maria, whom she cons into giving up an empty room for the use of the Neighbor's Club, and Yukimura, who she fools into working for the club as a crossdressing cosplay maid. The only person she can't insult is Rika, as Rika takes whatever insult she gives her and deflects it back with a dirty joke that leaves her tired – to the point where she just does what Rika says (like crossdress for example) rather than argue.
She is later revealed to be Kodaka's childhood friend, though at the time, he believed that she was a boy, calling her "Sora"; her nickname for him was "Taka." On the pre-arranged day before Kodaka moved, she intended to wear a skirt and reveal her gender to him but was too embarrassed to do so. Ten years later, she discovers that Kodaka has returned as a transfer student in her class, but does not acknowledge him or reveal who she is. When she is irritated, she immerses herself as a model student who talks with her imaginary friend "Tomo-chan" until she is discovered by Kodaka. She creates the Neighbor's Club in order to reform their friendship. Kodaka eventually recognizes her as his childhood friend after she cuts her hair short when it had caught on fire.

Sena Kashiwazaki (柏崎 星奈 Kashiwazaki Sena)
Voiced by: Kanae Itō (Japanese), Jad Saxton (English)
The wealthy blonde daughter of the school's headteacher, Sena shows a dislike of all things "ordinary". She is both attractive and academically successful, but her resulting arrogance excludes her from making friends with girls, and she treats her male classmates only as servants to be used, although many of them would like to be her boyfriend. Nonetheless, she holds Kodaka to a higher standard. Kodaka concludes that she is the weirdest member of the club,[citation needed] as she is able to warrant weird and disgusted looks not only from Yozora and Kobato, but also from Yukimura and Rika.
She enjoys playing video games, and will stay up late to advance in them or complete them. She particularly likes galge (games where the main character tries to win over a girl) because they allow her to make female (if virtual) friends,[ch. 4] although some of the games have embarrassing adult content. Although Yozora calls her "Meat" (肉 Niku?), Sena reveals she does not mind the insulting nickname because it is the first time she had ever received one.
Sena eventually develops feelings for Kodaka. In Volume 7 of the light novel, Sena learns that her father and Kodaka's father arranged for them to be married. In Volume 8, Sena proposes to Kodaka, asking him to marry her out of her love for him.

Kobato Hasegawa (羽瀬川 小鳩 Hasegawa Kobato)
Voiced by: Kana Hanazawa (Japanese), Alison Viktorin (English)
Kodaka's younger sister is a junior high student at St. Chronica's Academy; she is very close to her brother, who she calls "An-Chan", and behaves in a jealous and clingy way whenever she feels that he is not giving her the attention she deserves. After having watched an anime show called Iron Necromancer, she begins to call herself "Reisys V. Felicity Sumeragi", a vampire who has lived over a thousand years; she wears a gothic dress, wears a red contact lens as to appear to have heterochromia and drinks blood (tomato juice),although she still acts as a regular girl: she eats her vegetables and takes a bath when Kodoka tells her to, procrastinates on her homework, stays indoors when it is hot. She often speaks in an affected fashion, but when she gets emotionally worked up, she reverts to a strong Kyūshū accent.
When she joins the Neighbor's Club, she sees Maria as a rival for Kodaka's brotherly affections and often gets into fights with the her. Despite being older than Maria, she has smaller breasts.
Later on, when the Neighbor's Club visit her school to watch the film made by her class for the school festival (in which she was the lead actress), it was revealed that she was quite popular in school, but she has so far refused to befriend any of her schoolmates no matter how hard they try to befriend her.

Yukimura Kusunoki (楠 幸村 Kusunoki Yukimura)
Voiced by: Nozomi Yamamoto (Japanese), Ashleigh Domangue (English)
Yukimura is first introduced as a stalker of Kodaka. A gullible student with low self-esteem, Yukimura admiringly believes Kodaka to be a romantic and masculine outlaw who lives life the way he wants to, and eagerly pledges to become his "underling" to become manlier.Despite claiming to be a boy, Yukimura dresses in girls clothes, typically that of a French maid,or a bikini when at a water park or beach. In Volume 5, chapter 6 of the light novel, Kodaka discovers that Yukimura is actually a girl, even to Yukimura's surprise.
Yukimura refers to Kodaka as aniki (older brother), and tends to obey Kodaka's "orders" to the extreme; when Kodaka asked her to bring Maria something healthy to eat, she brought a protein shake and tried to force it down Maria's throat until she finished it all. Maria threatens to "Cut the cigar off that transsexual" for that forced feeding.

Rika Shiguma (志熊 理科 Shiguma Rika)
Voiced by: Misato Fukuen (Japanese), Alexis Tipton (English)
A first-year student who is a highly capable mad scientist that the school gives her a special room for her research, and excuses her from attending classes. Kodaka saves her when she falls unconscious during a disastrous lab experiment; she offers to repay Kodaka's kindness with sexual favors, and joins the Neighbor's Club just to get closer to him.
Among the girls in the series, Rika is the most sexually forward member. In her first speaking appearance, she describes the attractions of rape to Kodaka in the middle of a stunned class. She has a habit of inserting any sexual innuendo possible in her sentences, to the point where she finds it normal to convert any innocent thought into something perverted. As a fujoshi, she is a passionate consumer of BL (boys love) self-published magazines, but is especially aroused by stories that involve intercourse between mecha. She uses her genius-scientist and glasses-wearing image to divert others from her perverted nature. To compound her eccentricity, she speaks in the third person. In the light novel and the second season of the anime, she frequently changes her hairstyle.
In Volume 7 of the light novel, it was cleared that she's surprisingly the one who knows the most about Kodaka's feelings. In Volume 8, Rika agrees to be Kodaka's friend, making him the first friend she's ever got in her entire life.

Maria Takayama (高山 マリア Takayama Maria)
Voiced by: Yuka Iguchi (Japanese), Kristi Kang (English)
Maria is the supervising teacher of the Neighbors Club; she is a ten-year-old nun. While a child genius, she is also very rude and immature, and often uses a variety of expletives when annoyed. She develops a sibling-like relationship with Kodaka, who regularly makes her packed lunches, and is affectionate with him, much to Kobato's annoyance. She is easily manipulated by Yozora into doing things for her, usually when Yozora mentions that she gives her tasks an adult would do, or bribes her with a bag of potato chips.
In Volume 8, it was revealed that Maria was never a nun or teacher of St. Chronica's Academy in the first place, leading the Neighbor's Club to near-disbandment. Yet, Sena, with the use of his father's authority, was able to save the Neighbor's Club by appointing Maria as a special temporary lecturer for the club.

Pegasus Kashiwazaki (柏崎 天馬 Kashiwazaki Pegasasu)
Voiced by: Ryōtarō Okiayu (Japanese), Brandon Potter (English)
Sena's father and the chairman of St. Chronica's. He is a friend of Kodaka's father; they arranged for Kodaka and Kobato to attend the school.[LN 1] He is embarrassed by the unusual pronunciation of his first name, which would normally be "Tenma". He often badmouths Kodaka's father, but only because he truly values him as his best (and more or less only) friend. He seems intent to betroth Sena to Kodaka, often saying that he considers Kodaka to be "a man I can entrust Sena to", after misunderstanding Sena's intentions to make Kobato her younger sister. He is a wealthy man who wears traditional clothing, and is quite weak to alcohol (drinking two glasses and becoming drunk within seconds).

Stella Redfield (ステラ・レッドフィールド Sutera Reddofīrudo)
Voiced by: Ryōka Yuzuki (Japanese), Caitlin Glass (English)
The Kashiwazaki family butler and Sena's half sister. A blonde 22-year-old woman, she is a capable servant, though often surprisingly outspoken to her employer. She has a habit of making straight-faced jokes.

Kate Takayama (高山 ケイト Takayama Keito)
Voiced by: Emiri Katō
Maria's older sister who meets Kodaka and expresses her gratitude to him and the Neighbor's Club for taking care of Maria and keeping Maria's ego in check. She has a largely nonchalant attitude, and sometimes inappropriately belches or farts in public. Despite being relatively mature, she eventually calls Kodaka "onii-chan" (big brother) as well, since she is only 15 years old. In the anime, she appears briefly in season 1 episode 8, is introduced at the age of 15 in season 2 episode 2, and turns 16 in season 2 episode 7.

Aoi Yusa (遊佐 葵 Yusa Aoi)
Voiced by: Mariya Ise
The accountant of the Student Council of St. Chronica's. She is Sena's classmate and ranks second in the final year exam. She competes with Sena in her studies and is also envious of her popularity and other excellent attributes. She also attempted to disband the Neighbor's Club twice due to the club's lax performance and unmet requirements, but failed nonetheless after being faced with Yozora's and Sena's harsh scolding. She is first introduced in season 2 of the anime.

Hinata Hidaka (日高 日向 Hidaka Hinata)
Voiced by: Yōko Hikasa
Hinata is a third-year Student Council President of St. Chronica's. She is very popular in school and is a great athlete. She is first introduced in season 2 episode 10.