In a world very much like our own, great race horses of the past have a chance to be reborn as horse girls girls with the ears and tails of horses as well as their speed and endurance. The best of these horse girls go to train at the Japan Horse Girl Training Center Academy (Tracen for short), hopefully moving on to fame and fortune as both racers and idols.
Umamusume: Pretty Derby is Cygames' horse-based training and racing mobile game. The game was introduced in 2016 with a fast-paced trailer by P. A. Works, who would go on to do its anime adaptation in Spring 2018. In the interrim before the game's release, the project also launched three manga: Starting Gate! Umamusume: Pretty Derby, focusing on Special Week and Silence Suzuka's life in the school, Haru Urara Will Give Her All!, about the titular loveable loser training to become better throughout her racing career, and Umayon, a Yonkoma gag strip based on the anime.
- Ambiguously Brown: Hishi Amazon has a rather notorious tan.
- Cool Mask: El Condor Pasa wears a racing horse mask all the time.
- Cute Little Fangs: Daiwa Scarlet and Hishi Amazon have these.
- Exotic Eye Designs: Meisho has star-shaped pupils.
- Expressive Ears: Unsurprisingly horse girls have this.
- Fictional Sport: The Twinkle Series itself, combining aspects of track and field with the terrain of horse races and idol culture.
- Genki Girl: Toukai Teiou and Haru Urara are energetic and friendly.
- Idol Singer: The top scorers have to perform a Winner's Concert after their victory. Official tournaments also have the girls dress in idol clothes when they run.
- Little Bit Beastly: Horse girls are easily identified by their tails and ears.
- Mega Twintails: Daiwa Scarlet has some pretty impressive ones.
- Multicolored Hair: Some horse girls have this type of hair, not unlike the horses they're based on.
- Named After Somebody Famous: On this case every horse girl is named after actual race horses, and it doesn't matter if they were male or female. The ones named after females wear bloomers in training, the ones named after males wear shorts.
- Oral Fixation: Narita Brian always has a twig on her mouth.
- Peek-a-Bangs: Vodka and Air Groove have this style.
- Purple Eyes: Special Week has them, while Symboli Rudolf has a paler tone.
- Trope Overdosed: The trailer distilled its premise to amazing levels in the short two minutes it lasted. Personified racehorses? Personified racehorse idols? Figure skating personified racehorse idols? Schoolgirl Series and Sports Story gags in the middle of it all? The trailer features all this and more.