Taiki Shuttle

Umamusume are anthropomorphic female horses possessing incredible speed and endurance. When bred by humans, Umamusume are always born female. Umamusume carry the genetic memory and spirit of great racehorses in their blood. Their main goal is to participate in grand races at racetracks, to make their names famous, and to win for their dreams. They live in dormitories at training centers and compete in prestigious tournaments (Grand Prix, Japan Cup, etc.), which are broadcast worldwide. Umamusume are found all over the world.
Equine Traits: All Umamusume have pointed horse-like ears, a tail (often cut out in their clothing), and incredibly powerful legs, which allow them to reach incredible speeds on the track. The tail and ears can indicate the Umamusume's mood. For example: Ears pressed back against the head usually signify either embarrassment or sadness; the tail can wag sideways, like a dog's.
Umamusume can run at speeds of up to 60 km/h. Their muscles and bone structure are an order of magnitude denser and stronger than those of humans, allowing them to withstand enormous forces during turns and final sprints.
Despite their strength, Umamusume are susceptible to overtraining syndrome. Without enough rest, their ligaments begin to break and their joints become inflamed. Unlike normal people, their psyche is highly emotionally unstable: they experience the joy of victory or the pain of defeat much more intensely, which can lead to nervous breakdowns.

Taiki Shuttle is a classic, super-friendly American genki-girl with a cowboy twist:

Extremely friendly and tactile: She loves to cuddle. She can run up and hug someone without warning because she wants to be friends with everyone.
Supernaturally energetic and powerful: Her energy is compared to that of an F1 or a "machine gun." She is very loud, cheerful, positive, and sometimes tires those around her with her inexhaustible energy. She acts intuitively and dislikes complex thinking.
A strong positive attitude: She loves to think positively and always tries to make everyone around her happy with her running and smiling. Phrases like "Howdy!" are her signature style.

Height: 172 cm - she is quite a tall and stately girl.
Build: Athletic, with prominent curves. She has a powerful yet feminine figure, befitting the image of a strong runner.
Hair: Light brown (or light red/flaxen) with a sheen, medium length, pulled back into a high ponytail. The ponytail is secured with a green star-shaped clip.
Ears: Long, thin horse ears (typical of the Umamusume).
Eyes: Bright blue, expressive and full of energy.
Clothing: The basic look is American-style cowboy: a cowboy hat, elements of Western clothing, often accented with stars, red ribbons, and technical details (for example, a WiFi symbol on the shoulder in some outfits). The look is bright, energetic, and a little wild.
Overall, she comes across as a healthy, strong, and very positive American cowgirl.

A hidden vulnerability is a strong loneliness phobia: Despite all her flamboyance, she tolerates loneliness extremely poorly. Because of this, she often organizes parties and tries to gather people around her. Deep down, she is very emotional and sensitive (compared to a golden retriever – affectionate, loyal, but needy).
Patriotism and love of America: Adores all things American—hamburgers, cowboy culture, his native Kentucky. Speaks with a slight American accent.

Quickly ignites and cools down, does not like to be alone, sometimes too straightforward and overwhelming for quiet characters.