A gray-haired, easygoing girl who transferred from a regional circuit. After a winning streak 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 ditsy. She is the biggest glutton at Tracen Academy, capable of emptying a rice bin or a pot in an instant. The public calls her the "Gray Monster."

A petite chestnut-haired Horse Girl. She is Oguri Cap's teammate. She has excellent grades in classroom studies and possesses superior 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 regional drawl. Though small in stature, she is a bundle of pure willpower, constantly delivering sharp retorts in daily life and on the race track whenever she sees an opening. Growing up in a financially struggling environment, her hunger to prove she won't lose because of her background is the source of her power. She is Oguri Cap's rival.

The trainer for Oguri Cap and Bernie Light. A tall man who appears to be in his prime. Roppei is his uncle. He witnessed Oguri Cap during a gate test and, with eyes shining, scouted 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 gap in their abilities during a race with Oguri Cap, she had a change of heart. She now supports Oguri Cap while teaching her the dances for the Winning Live. Her family runs a dance school. She is a hardcore fan of Oguri Cap.

Norn Ace's childhood friend since elementary school. She has long, dun-colored hair, which is rare for a Horse Girl. A delinquent-style girl with a sharp gaze and a foul mouth.

Norn Ace's childhood friend since elementary school. Characterized by her dark bay bob cut and blinkers. She is quite crafty and prone to schemes.

Oguri Cap's first rival, featuring pale light-blue hair in an uneven straight cut and red eyes. She gives a cool, unapproachable impression and possesses a powerful obsession with victory. Even after Oguri Cap left for Central, she remains conscious of her and works hard at Kasamatsu to remain her rival.

A female trainer at Kasamatsu Tracen Academy characterized by her freckles. She serves as the trainer for Norn Ace, Rudi Lemono, and Minnie the Lady. She apparently wanted to train the scholarship student, Fujimasa March. She is usually scowling because her "three idiots" are always plotting schemes instead of training. Looking at Minoru Kitahara, who ended up in charge of Oguri Cap for Central races, she 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.