(167cm, Gray) First person: I (pure, polite) Known as the "Gray Monster." Somewhat large in stature. A thoroughly innocent gray filly, she is voracious when it comes to running and eating, but indifferent to almost everything else. Possessing a flexible body, her signature move is a double spurt. She loves her mother and everyone back at Kasamatsu. She belongs to Kitahara's team after his persistent scouting and places great trust in him as a mentor. Her primary motivation is responding to the expectations of those who find joy in her running and winning. Her skill is top-tier even in Central, shattering the jinx that grays like Tamamo can't win. She proved her worth through her performance to those who dismissed her as just a regional racer.

(146cm, Chestnut) First person: I (modest, polite) A shy, petite Umamusume. She sits next to Oguri in class and becomes her friend while looking after the overly eccentric girl. She joined the team alongside Oguri when she accepted Kitahara's scout. Since her family runs a sporting goods store (a major chain with branches in Tokyo as well as Kasamatsu), she decides to dedicate herself to a support role for Oguri during her career transition.

A trainer at Kasamatsu who laments the lack of star Umamusume in the regional circuits. A slightly romanticist older man who can't let go of his dreams; he was once caught by Oguri excitedly jogging while providing his own play-by-play commentary as if he were a racer. He was captivated by Oguri's running while observing a freshman class and decided to become her trainer. When Oguri was invited to Central, he entrusted her to his uncle, Ginjiro Roppei. He eventually obtained a Central Trainer License and moved to Central to become Oguri's trainer once again.

A Central trainer and Kitahara's uncle. He was the one who sent his nephew, who was idling after quitting his job, to Kasamatsu when they needed a trainer. Kitahara calls him "Roppei-san." He is rarely seen without his sunglasses. He took over as Oguri's trainer when she moved to Central because Kitahara lacked a Central license, acting as a placeholder until Kitahara could join them. A highly skilled veteran who has raised numerous G1 champions, he recognized that Oguri needed to "change her way of fighting" and adapted her running style for Central turf.

(140cm, Gray) Petite. First person: I (Kansai dialect) Known as the "White Lightning." A small gray Umamusume from Central who speaks with a regional drawl. Raised in poverty, she possesses an indomitable spirit that refuses to lose. Her professional gaze toward racing proves she belongs in Central. She is the other "monster" who, alongside Oguri, broke the jinx against gray horses. She specializes in overwhelming late-stage charges befitting her nickname, but tends to get nervous before races and has a small appetite, contrasting with Oguri. She possesses absolute power in Central.

(Height unknown, somewhat small, Chestnut) First person: I (rough, masculine) Known as the "Chestnut Bullet." She has a defiant personality as her appearance suggests, but at the academy, she is friendly enough to chat normally with Ardan and others (and occasionally ruffles Chiyono O's hair). Even Yaeno and the others view her as a superior competitor. Though her record suffered due to injury, she made a grand comeback at the Hakodate Kinen, beating Merry Beauty and setting a Japanese record for the 2000m turf. For some reason, she insists on wearing a hood over both her racing silks and school uniform.

(159cm, Bay) First person: I (formal, polite) A "Sturdy and Simple Martial Arts Girl." She is highly disciplined and has a quaint habit of writing formal challenges before a match. Among the Central group, she is perhaps the one who evaluates Oguri's skill most highly, though she also harbors a complex regarding the gap between their abilities. Despite her straightforward impression, she is a tactical racer who keeps others from cutting inside while maintaining a position to overtake from the far outside. She usually addresses others with the honorific "-dono."

(168cm, Bay) Large. First person: I (gentle, feminine) A classmate of Oguri in the Central group, she is quite close to her, along with Mejiro Ardan. She is often seen watching races with Dicta Striker and Yaeno. While the public initially saw her as just another racer, her status skyrocketed after the Kikuka-sho. She has a very maternal nature and loves to pamper Tamamo, Oguri, and other Umamusume.

(139cm, Bay) Petite. First person: I (tomboyish, Edokko dialect) An Umamusume from the regional circuits, just like Oguri. Upon her first appearance, her fiery personality and well-built physique despite her small stature greatly surprised readers. Depicted as much more hot-blooded than her game counterpart, her goal is to make a name for herself by showing up Oguri Cap and the other Central racers.

[Yayoi Akikawa] The Chairwoman of Tracen Academy! Behind her boisterous tone and behavior lies a strong will to support all Umamusume. Her support is so generous she sometimes spends her own fortune, earning her the respect and gratitude of the students. However, she is frequently scolded by her secretary. [Tazuna Hayakawa] The Secretary to the Chairwoman. A kind supporter for trainers, students, and the Chairwoman alike. With a desire to provide a comfortable academy life, she handles a wide range of duties from paperwork to managing bulletin boards. She sometimes catches curfew breakers, showing that her leg strength is as top-tier as her administrative skills. It is unknown if Tazuna and Yayoi are Umamusume; it's considered a topic better left untouched (in reality, they are). Top Secret: Names from their active racing days: Tazuna: "Tokino Minoru" / Yayoi: "Northern Taste"