Uma Musume Pretty Derby (promo ONA)

The characters featured in this video are Silence Suzuka, Oguri Cap, El Condor Pasa, Daiwa Scarlet, T.M. Opera O, Special Week, Hishi Amazon, King Kamehameha, Taiki Shuttle, Maruzensky, Mejiro McQueen, Vodka, Symboli Rudolf, Tokai Teio, Narita Brian, Seiun Sky, Deep Impact, Orfevre, and Haru Urara.

Animation Error: When Daiwa Scarlet wakes up, she is seen with both human and horse ears.

This promo video nearly destroyed the whole project, as several owners of the racehorses that inspired the characters were upset by its yuri themes; some of them retracted their licenses to the racehorse names from the project. In one scene, King Kamehameha is shown hitting on Hishi Amazon at the beach and the racetrack. The most infamous scene involves Symboli Rudolf and Oguri Cap's as an ice skating couple.

Makoto Kaneko, the owner of King Kamehameha (2001-2019) and Deep Impact (2002-2019), left the project after the release of this video. After seeing the video's yuri overtones, he stated in several interviews that he will never license his racehorses to any franchise. However, it is highly suspected that Kaneko fears Deep Impact's 2006 doping scandal might be incorporated into Uma Musume's storyline.

The uma musume who gets her face mask ripped off by the duel between Narita Brian and Deep Impact is based on Orfevre (foaled May 14, 2008). Sunday Racing, the owners of Orfevre, pulled out of the project after the release of this video, but in 2023, Cygames was able to negotiate a deal to bring Orfevre and Gentildonna (2009-2025) into the game.

The video game was originally announced to be released in 2018 alongside the anime series, but it faced numerous production delays. It was originally designed in a landscape format that was more suited for PCs and tablets, but when someone at Cygames suggested to use a portrait format to better suit smartphones, the game had to be redesigned from the ground up. Eventually, the game was released in February 2021.