Yamato Nadeshiko: Sawako is a fine example of this trope. First of all she looks the part with the black hair and Hime Cut. Second she's kind and helpful to the point of Extreme Doormat but not entirely pilable. Third she takes turns cooking for her family and is a good cook to boot.
Sawako's classmate and the most popular guy in school. On the first day of school, he got lost and was given directions by Sawako. He has since admired her and developed a crush on her, and is apparently the first person to ever stick around Sawako long enough for her to clear up a misunderstanding, and give her a confidence boost necessary to make more new friends.
Lovable Alpha Bitch: She's fastidious about her appearances and socially adept, but turns out to be very kind.
Manipulative Bitch: In a (usually) positive sense. She would make a great scheming shoujo manga villian, but fortunately she's on Sawako's side.
Not What It Looks Like: In the manga, when Pin sees Ayane with a swollen cheek (after having been slapped by her college ex-boyfriend for suggesting to break up), he automatically assumes a guy in the class did it.
Urban Legend Love Life: While rumored to have got around in middle school, Ayane has a college boyfriend. However, when she suggested breaking up, her boyfriend slapped her. Despite his apologies, she broke up with him anyway because of how clingy he had been acting.
Yano's other half, and the more physical of the duo. Yoshida shares most of Yano's concerns regarding Sawako. She shows great athletic prowess and occasionally suffers lapses in "ladylike"-ness. Yoshida also displays romantic interest in Ryu's brother at first, and, seemingly and unbeknowst to herself in Ryu too.
Best Her to Bed Her: From the early in the series when we learn that Ryuu is the only guy she's never defeated, we can guess what's going on. And then, in chapter 51...
In fact, she's so used to dressing up in boyish clothing her plan to wear a mini-skirt was a big plot point.
She actually wears a dress when attending Tooru's wedding.
Trademark Favorite Food: Yoshida developed a love for ramen after constantly visiting Ryuu's family ramen shop in her childhood. A background conversation even details her wish to "be a ramen" when she grows up.
Mostly silent, athletic, and non-judgmental classmate of the others. The few things he does say range from hilarious non-sequiturs to insightful meditations on human nature. He's in love with Chizu, and has been for a very long time.
Spiky-haired, slightly delinquent-looking young substitute teacher of Sawako's class. Usually acts loud, cheerful and full of himself and likes to order around Ryuu and Kazehaya, whom he's known since the latter's childhood. Also has a strong fear of paranormal things and is extremely suspicious of Sawako.
Pet the Dog: In Chapter 45, when Ayane confesses that she doesn't believe she's kind (compared to Sawako and Chizu) because of how cunning she can be in front of Pin, she dreads another Small Name, Big Ego lecture from a surprisingly quiet Pin, who instead stares at a candy Ayane gave him because he was whining about not getting one after the festival. Then, Pin literally pats Ayane on the head and reassures her that she is kind before walking up the stairs, leaving Ayane (and the readers) speechless that Pin could actually BE a nicer guy than he usually shows.
Manipulative girl with a crush on Kazehaya. She prefers the nickname "Kurumi," and uses this level of familiarity to gain Sawako's trust and sympathy. Her plan backfires, and instead leads Sawako to acknowledge her own feelings for Kazehaya. She also starts rumors about Yano and Yoshida, and pins them on Sawako to break up their friendship.
Because You Were Nice to Me: As it turns out, her reason for liking Kazehaya isn't so different from Sawako's. He was the only person to treat her as someone with feelings, and saw through her happy facade and noticed that she was hurting back in middle school.
Only Known by Their Nickname: For the record, his actual name is Kento. Names of Japanese origin like Kento are written with kanji, and should be fully spelled out when romanized. The name Kent, on the other hand, is vaguely implied to be a nickname. Kent is the name seen most often (whether it be due to amateur translation or something else), so it has stuck with most of the fanbase.
Romantic False Lead: He sincerely wants to help Sawako connect more with her classmates, but his implied interest in her and the damage he does to Sawako and Kazehaya's relationship (though unintentional, because when Kazehaya told Kent that he liked someone, Kent told Sawako that she should give up on Kazehaya, unaware that Kazehaya likes Sawako) makes him one.