Horse Girls

Horse Girls (ウマ娘, Uma Musume) are the reincarnations of racehorses from another world. Their fate is to forever run towards their goals.

Visibly, horse girls are human girls who possess horse features. They have horse ears instead of a human's and a tail that matches their hair color. They are also blessed with incredible speed and stamina, which grants them the ability to race others of their kind. Horse girls are well known amongst mankind and appear to be greatly adored by them as well.

On May 4th 2018, the Anime staff revealed more information about the Horse Girls and their world. During a "question corner" segment, they revealed that: (source )
 * There are no normal horses in the world of the anime
 * Uma Musume can run on walkways
 * There are cases of relationships between humans and Uma Musume
 * There are no known Uma boys
 * The fathers of Uma Musume are a secret
 * Uma Musume are like elves
 * There is no betting with an Uma Musume race; it's something like watching sports
 * Some Uma Musume are active in other competitions
 * There are training center academies outside of Tokyo
 * There are Uma Musume who are not good at running but like singing (in the game), and also vice versa