A gray-haired, easygoing girl who transferred from the regional circuit. After a streak of consecutive victories in her hometown, she arrived at Tracen Academy carrying everyone's expectations. While she intends to work hard to honor those hopes, her behavior is completely airheaded and doting. She is the biggest glutton at Tracen Academy, capable of emptying a rice bin or a cooking pot in an instant. The public calls her the "Monster of the Gray." She wears her hair in a ponytail. During the Kasamatsu arc, she never wore a uniform, always sporting a slightly dirty tracksuit, but she wears the school uniform in the Central arc. Her trademark diamond-shaped hair ornament was once worn by her mother when she was an active racing Horse Girl. Born with poor knees, she was unable to walk at birth; it was only after receiving daily knee massages from her mother that she finally became able to walk and run. She loves running, and because of her past knee issues, she often says, "To me, being able to stand and run is a miracle in itself." She entered Kasamatsu Tracen Academy simply wanting to run, but after being questioned by Fujimasa March about her lack of ambition, she began to focus on winning. While she loves running, she is indifferent to almost everything else and lacks knowledge about racing Horse Girls or local series. This led her to enter a race in broken shoes, and after winning, she didn't understand how Winning Lives worked and danced the Kasamatsu Ondo [Note 1], leaving the audience stunned. Her airheadedness remains unchanged; she often interprets harassment or sarcasm as kindness, or takes things so literally that her responses end up inadvertently provoking her opponents. Her family was poor, living in a run-down apartment with just her mother. Her appetite is beyond human (or horse) comprehension; her mother once told her, "(Tracen Academy's tuition) is nothing compared to your food expenses." Even at the Kasamatsu Tracen Academy cafeteria, which was supposed to be "all-you-can-eat," she was eventually told "closed for the day" because she ate too much.

A petite chestnut-haired Horse Girl. Oguri Cap's teammate. She has excellent grades in classroom studies and possesses sharp insight and analytical skills. Her family runs a major sporting goods store specializing in Horse Girls, giving her deep knowledge of equipment. She is Oguri Cap's best friend.

A tiny gray-haired girl with a thick Kansai accent. Though small in stature, she is a bundle of sheer willpower, constantly firing off quips in daily life and on the race track. Raised in a financially struggling environment, her hunger for success—refusing to lose because of her background—is the source of her power. She is Oguri Cap's rival. Her skills are top-class even in the Central circuit.

The trainer for Oguri Cap and Bernie Knight. A tall man who appears to be in his prime. Roppei is his uncle. He witnessed Oguri Cap during a gate test and scouted her with sparkling eyes, seeing her as a talent who could aim for the Tokai Derby together with him.

Called "Uncle Roppei" by Kitahara, he is the benefactor who invited Kitahara into the world of training. He has raised numerous G1 Horse Girls at the Central Tracen Academy.

After realizing the vast difference in skill during a race against Oguri Cap, she turned over a new leaf. She now supports Oguri and teaches her how to dance for Winning Lives. Her family runs a dance studio. She is a hardcore fan of Oguri Cap.

Norn Ace's delinquent friend since elementary school. She has long palomino hair, which is rare for a Horse Girl. A sharp-eyed rebel girl with a foul mouth.

Norn Ace's delinquent friend since elementary school. Characterized by her black hair in a bob cut and her racing hood. She is quite crafty.

Oguri Cap's first rival, possessing light-teal tiered straight hair and red eyes. She gives off a cool, unapproachable impression. Even after Oguri left for Central, she remains conscious of her, working hard at Kasamatsu to remain her rival. A short-distance specialist with excellent explosive speed that feels like a sharp cut, she uses a front-running style and has great racing intuition. Her goal is to win the Tokai Derby, and she shows raw fighting spirit toward Oguri, acknowledging her talent. It appears she is from the same district as the "Three Idiots" (Norn Ace and her friends), and it is established that she belonged to the same racing club. While she carries herself with a cool, honor-student demeanor, her academic performance is somewhat questionable. She also has a playful side. During the Winning Live of her debut race, she was depicted blushing and enduring the embarrassment of the skimpy live outfit. She also shows a clumsy side, such as when she unintentionally kept glaring at her roommate, Walk Dancer, while trying to find the right timing to talk to her.

A female trainer at Kasamatsu Tracen Academy, characterized by her freckles. She is the trainer in charge of Norn Ace, Rudy Lemono, and Minnie the Lady. She apparently wanted to be in charge of the scholarship student, Fujimasa March. She is usually scowling, likely because the "Three Idiots" are always plotting mischief instead of training. She observed Minoru Kitahara, who took charge of Oguri Cap in the Central races, from a trainer's perspective and spoke as if she didn't even want to imagine the pressure he was under. Her name and background as a former delinquent were revealed in Volume 2 of the manga.