Dude Magnet: Subverted. She would be one due to her looks, but men are usually driven off by her personality.
Lampshaded in the episode 16 when the male members of the club decide which one of their female collegues they'd rather have as a girlfriend. When Nishida and Komano declare Chihaya 'out of question' Taichi is upset... but after they present their arguments (Chihaya being Married to the Job and a maniac about karuta) he sees no option but to admit they're right and gives off his vote to Kana-chan too.
The Unfavorite: Subverted as her parents seem to come off as uncaring toward her at first when they seem to have endless picture albums of her older sister and her modeling career, but it turns out that they're overjoyed at the fact the can collect newspaper clippings of both their daughters. Chihaya's only just started.
Except that they ignore her when she wins her first karuta tournament (which is probably her first big success) in favor of Chitose's photo-shoot.
Unskilled, but Strong: She's incredibly fast, but has no technique. In episode 17, both Tsutomu and Kana-chan point out her weaknesses, which actually pulls her out of her Heroic BSOD after Harada-sensei points out to her the problem of relying over much on speed. In episode 18, it's all but spelled out to her why her over reliance on her speed and sharp ears isn't the best way to play.
Weak, but Skilled: Not that weak, as Taichi is pretty athletic and doesn't come off than less physically capable than the other players, but the balance certainly leans this way, especially compared to the likes of Chihaya. Taichi is well aware than his physical skills don't match his thinking abilities, too.
Always Someone Better: In Taichi's eyes anyway. And Nikuman's. And Retro's. And, as it turns out, even Shinobu's. Looks like everyone close to him in age and who knows him well, with the exception of Chihaya, has a sizable 'Arata complex' in the karuta field.
Serious Business: Traditional Japanese clothing to the point where she joins the club on the condition that they start wearing hakamas. She gets it from her mom.
The actual hundred poems as well. She takes it as a personal affront to be berated on her card arrangement by Nishida when he doesn't know any more about the cards than how he arranges them for ease of play compared to her, who knows them all by heart.
Shipper on Deck: She's very supportive of the prospect of Taichi and Chihaya being together, even despite having sympathy for Sumire and realizing that Chihaya likes Arata.
Hidden Depths: You wouldn't take that mean, chubby kid met in grade school tournament seriously, but after years he proves himself as a decent player, valuable team member and, despite his appearance, a guy athletic enough to win a relay race for his team.
Thinks Like a Romance Novel: She views herself as the "main character" of a shoujo series due to her slightly above average looks, plus having a beautiful rival to defeat for her love interest's affections. Just as well, she first becomes interested in joining the karuta club because the one-hundred poems are a collection of love poems.
Eyes Always Shut: Though when he opens them he instinctively licks his lips creeping people out.
Glory Hound: To his credit, this trait makes him try harder to improve... and occasionally, cheat.
Suicidal Overconfidence: He's sure of winning a game in the tournament despite not winning any during the practice, to the point of trying to swindle with a list of his team players' names. Given the chance, he loses. Several matches later he tries this trick a second time... in the finals.
Hidden Depths/Took a Level in Jerkass: In the first season he looks like he's just easy-going and you can feel bad for him when he's being creamed by Shinobu. In the second season he comes off as rather cheap and unsympathetic when he berates Hyoro for wanting to give the best shot.
The captain of the Fujisaki team and an A Class player. Serious-looking and even perceived by Taichi as similar to Arata, but his personality is in reality quite different. A third year student.
Covert Pervert: Well, not exactly covert (his whole school knows the fact), but to the strangers he looks like a calm, seious type, so it comes off as a surprise.
Has a Type: And the type has big boobs. Eromu has hots for Sakurazawa-sensei, took an interest in Kana and regretted deeply that he couldn't play against her "lovely jugs". And the reason of his lack of interest in Rion? Oh come on, she has breasts of an infant.
Stoic Woobie: Bullied and discouraged by most of her schoolmates, stuck in Class B...
Other prominent karuta players
The current and youngest Queen of Karuta
Adorkable: Despite being a beautiful, aloof epitome of Lady of War in karuta for most of the time, Shinobu's love for Snowmaru, her fashion senses and tendency to make weird facial expressions at times (probably most notably during her first on-screen encounter with Arata) make her cross into this territory.
But for Me, It Was Tuesday: Treats this way her matches with Sudo and Yumi Yamamoto. Taken to ridiculous level in the second case, because Yamamoto is the former Queen, whom Shinobu was playing previously exactly at the occasion of taking the title from her.
Smug Super: in a sense being the Queen of Karuta. She goes on and on berating team tournaments, karuta societies and basically almost everyone, whose level or potential in the game she sees as inferior.
The Resenter: Toward Shinobu and Chihaya, who, in her mind, represent a certain type of person: a lively, beautiful and talented high-school girl, who would take everything from her effortlessly. Note that Yumi herself is a rather plain young woman (no Generic Cuteness here) with the probably not very fulfilling job of an Office Lady, whose Hard Work Hardly Works in the karuta field, so it's kind of understandable.
A college student and the current Meijin. He's been holding this title 4 years in a row.
Book Dumb: He's the king of Karuta, but he's stuck for eight years in college (to the point, where all the karuta officials beg him to graduate already) and he doesn't come off as an intellectual type in general.
Which might be a case of Brilliant, but Lazy, because later it's revealed that he's a Toudai student.
Super Senses: His hearing ability is so remarkable that he can catch the sound before it barely leaves the reader's lips.
The Unfavorite: In karuta environment. At least in the eyes of the officials, who consider him a bad role model and generally can't stand him to the point of willing to bend tournament's rules for Arata, so he has a bigger chance to replace Suou someday.