The "Gray Monster." A profoundly innocent gray-haired freshman. She is voracious when it comes to running and eating, but indifferent to almost everything else. Her trademark is a spurt performed in an extreme forward-leaning posture, made possible by the flexible body she developed through her mother's efforts. Since this is before her transfer to Central, she wears her hair in a ponytail. She loves her mother dearly. After being scouted by Kitahara, she joins his team. Initially seeing him just as "the person who lets me race," she gradually comes to trust him as a mentor, and they develop a bond as comrades pursuing the same goal. Thinking of those who are happy when she runs and wins, meeting their expectations eventually becomes her greatest driving force.

A shy, petite Uma Musume. She sits next to Oguri in class and becomes her friend while looking after the overly eccentric girl. She joins the team alongside Oguri after the latter accepts Kitahara's scouting. Since her family runs a sporting goods store (a major chain with branches in Tokyo as well as Kasamatsu), she has strong opinions on racing gear and decides to dedicate herself to a support role for Oguri during her turning point.

A trainer at Kasamatsu who laments the lack of star Uma Musume in the regional circuits. He's a bit of a romantic middle-aged man who can't let go of his dreams; he was once spotted by Oguri frolicking during a jog while providing his own play-by-play commentary as if he were a racer. He becomes captivated by Oguri's running while observing a freshman class and aims for her to compete in the Tokai Derby, the highest-grade race in the Tokai region and a dream stage for Kasamatsu students. He is a complete amateur when it comes to Winning Live performances. When Oguri was invited to Central, he entrusted her to his uncle, Ginjiro Musaka. He later obtained his 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 threw his nephew into Kasamatsu when they needed a trainer while he was unemployed and smoldering. Kitahara calls him "Roppei-san." He seems to have favored sunglasses for a long time. He visits Kasamatsu to watch the Junior Crown while on vacation. He tries to stop Kitahara from running Oguri in the Chukyo Hai with the Tokai Derby in mind, using few words. This later becomes the indirect cause of a certain conflict, but he takes Oguri on as her trainer after her transfer to Central, promising to look after her "until Kitahara comes to Central." His skills as a trainer are top-notch; he realizes that "the way she fights needs to change" and alters Oguri's running style to suit Central turf.

The "White Lightning." A petite gray-haired Uma Musume in a Central uniform. She speaks with a regional drawl (Kansai accent). She grew up in a financially difficult environment but possesses a spirit that refuses to lose. Her affiliation with Central is no fluke; her gaze toward racing is that of a seasoned professional. Along with Oguri, she is another "monster" who broke the jinx that "gray horses don't run" and began a rapid ascent. She specializes in an overwhelming closing sprint worthy of the name "White Lightning," but she tends to get nervous before races and, in contrast to Oguri, has a small appetite. She possesses absolute power within Central.

The "Chestnut Bullet." She has a competitive personality just as she looks, but at the academy, she seems well-integrated enough to chat normally with Ardan and the others (she reportedly occasionally fluffs Chiyono O's hair). Yaeno and others view her as a superior presence. Although her record suffered due to injury in the first chapter, she made a grand comeback in the Hakodate Kinen after her return, beating Merry Beauty and setting a Japanese record for the 2000m turf. For some reason, she sticks to a fashion style(?) of wearing a hood over both her racing silks and her school uniform.

The "Fortitude and Simplicity Martial Arts Girl." She welcomes Oguri, who achieved overwhelming results at Kasamatsu, with proper etiquette; she has an old-fashioned side, such as writing a formal challenge before a match. Among the Central group, she is in a sense the person who evaluates Oguri's ability most highly, and she also has a side that feels an increasing complex regarding the gap between her own strength and Oguri's. Despite her straightforward impression, she is a skilled tactician in races, keeping Oguri from cutting inside while she herself maintains a position to overtake from the far outside.

A fellow Central student and Oguri's classmate. Along with Mejiro Ardan, she is quite close to Oguri. She often watches races with Dicta Striker and Yaeno. While she was seen by the public as an Uma Musume who was just one step short, she turned things around starting from the Kikuka-sho to reach the top tier. She has a motherly nature and dotes on Tamamo, Oguri, and other Uma Musume.

An Uma Musume from the regional circuits, just like Oguri. When she first appeared in the main story, her Edokko (traditional Tokyoite) temperament—derived from her motif—and her well-endowed physique despite her small stature greatly surprised readers. Compared to her game version, she is depicted as a much more hot-blooded Uma Musume, aiming to make a name for herself and show up Oguri Cap and the other Central Uma Musume.

[Yayoi Akikawa] Our Chairwoman of Tracen Academy! Behind her bold tone and behavior lies a strong will to support all Uma Musume. She earns respect and gratitude from the students for her generous support, sometimes even spending her personal fortune. However, she is frequently scolded by the Chairwoman's Secretary. [Tazuna Hayakawa] The Secretary to the Chairwoman of Tracen Academy. A kind support figure for trainers, students, and the Chairwoman. With the desire to "provide a comfortable school life," she handles a wide range of duties, including paperwork and managing notice boards. She sometimes catches those breaking curfew, showing that her leg strength is top-class in addition to her administrative skills. It is unknown if Tazuna and Yayoi are Uma Musume; it is considered a topic better left untouched. TOP SECRET: Names from their active days Tazuna: "Tokino Minoru" / Yayoi: "Northern Taste"