An Official Alternate Costume of Umamusume's Oguri Cap (Umamusume) originating from the Umamusume: Cinderella Gray manga.
In the manga, she wears it for the finale, the Arima Kinen (based on the 1990 Arima Kinen, the real-life Oguri Cap's final race). Her in-game aptitudes and Skills reflect this – for example, she has Mile/Long aptitudes instead of Mile/Medium.