Bad Export for You: The Simplified Chinese version of the game was launched on August 30, 2023, but was suddenly pulled from app stores eight days later on September 8 for "technical updates". The game's servers were kept online despite this, and had content updates for the first six months of service. As the game was still unavailable on app stores after the six months mark had passed, it cannot implement any new content that was added after the mark, with the last update on its official Bilibili page made on March 2024. It's commonly speculated that it was actually taken down for violating Chinese censorship laws promoting gambling, as the game is about moe anthropomorphized racehorses, after all. The game was eventually brought back in May 22, 2025, but with anti-horse gambling censorships to comply with the regulators, such as the removal of horseshoes and horse tails from the girls.
Dummied Out: Interestingly, looking at the game's animations with an application like UmaViewer will reveal that Happy Meek has a unique win animation, despite the chances of her becoming a scoutable trainee being slim to none due to her being both an original character made for the game and already canonically having a trainer in Aoi Kiryuin. Whether this means the developers do want to make her trainable in some way remains to be seen.
Development Hell: Umamusume: Blue Sky is a manga series centered around Seiun Sky that was announced in late 2018 as a follow-up to a Seiun-centered light novel, predating Umamusume: Cinderella Gray, Umamusume: Star Blossom, and Umamusume: Peace Peace☆Supi Supi Golshi-chan. However, its planned mangaka, Yoshihiko Watanabe, left CyComic before the project could be started, leaving no one to work on it. Since then, no further news has come out about the manga.
The accessory near an Umamusume's ear indicates on whether their real-life counterpart was a stallion (right) or a mare (left). Notably, Fine Motion has matching accessories on both ears as a reference to the real-life horse being intersex. Inversely, two mob Umamusume from the animated adaptation are depicted with no accessories, as their real-life inspirations are geldings.
The chest size of an Umamusume is usually based on the leg musculatures of their real-life inspiration, with muscular horses being usually depicted with a large chest as an Umamusume and lanky, slim horses being depicted with a small chest as an Umamusume.
Ascended Meme: One of the Career events added to the game post-launch (for the JP server's 1st anniversary, and the Global server's half-anniversary) was a random event in Tokai Teio's scenario named "You Can't Have It!" that basically functions as an extended reference to the memetic "AGEMASEN!" Imagine Spot Teio has in the anime.
With the exception of Ardan and Ramonu, the Mejiro girls are cousins, not sisters as often presumed. This confusion is confused by McQueen and Bright referring to Ryan as sister on multiple occasions, but the use there is meant to be metaphoric.
Actor-Shared Background: Tosen Jordan loves eating hamburgers, much like her voice actress, Eri Suzuki.
Examples of real-life merchandise based on the franchise include the plushies you can get in the arcade and the yakisoba sold by Gold Ship in the anime, But not available in Oguri Cap-sized portions, however.
