Grass Wonder, one of the real-life racehorses that inspired a character in Umamusume: Pretty Derby, passed away on August 8 at age 30, prompting an outpouring of condolences from fans of Cygames’ anime horse-girl franchise.
The stallion Grass Wonder is one of the real-life Japanese racehorses Cygames turned into a character for its Umamusume: Pretty Derby anime and games. As all Umamusume’s characters are anime girls with equine ears and tails, Grass Wonder also got a sex change. In the Umamusume universe, Grass Wonder is a friendly but determined girl who grew up in America but loves Japanese culture, echoing how the real horse was American-bred but trained in Japan. The character’s light brown hair with a white dot at the front mimics the horse’s chestnut coat with a white star marking.
The real Grass Wonder is known for winning Arima Kinen, one of Japan’s prestigious Grade 1 races, twice. During his four-year career (1997-2000), he placed first in nine out of 15 races. At the time, Grass Wonder was matched against fellow racehorse Special Week (resulting in a tense photo finish back in 1999), and this rivalry is portrayed in the Umamusume: Pretty Derby anime. After retiring from racing in 2000, Grass Wonder went on to sire four champions including Screen Hero and Earnestly.
According to the official obituary from Big Red Farm, where Grass Wonder lived out his twilight years, the former champion racehorse was in good health until he started to decline yesterday evening. He passed away from age-related multiple organ failure at the age of 30, an impressive age for a racehorse.
In response to the news about the real Grass Wonder going to the great big pasture in the sky, Umamusume’s official X account posted: “On August 8, we received the news that Grass Wonder, one of the horses that served as inspiration for a character in our franchise, has passed away. We would like to extend our condolences to all related parties, and pray for the repose of this champion horse’s soul.”
Fans also posted messages of condolences, with many hoping that Grass Wonder was now in a place where there are plenty of dandelions (his favorite food). “The last horse from the strongest generation has set off on his final journey… Thank you Grass Wonder,” one commenter posted. Another pointed out that although they feel sad when the real horse behind a character passes away, the horses will keep on shining forever in the world of Umamusume.
By coincidence, Rena Maeda, who voices Grass Wonder in Umamusume: Pretty Derby, posted on X yesterday about her experience visiting the racehorse in real life. She said she intends to go back and see him again, although sadly she won’t get the chance.
海外のトレーナーさんたちが2018年のこのポストを見つけてくれている！ありがと！
Trainers from overseas are watching this post! Thanks !!
This photo was taken in 2018 when I went to see Grass Wonder in person as a voice actor playing the role of Grass Wonder.
He was eating lots of… https://t.co/aOFOZThVHu
— 前田玲奈(◜‧̮◝ )ﾏｴﾚﾅ (@renamaeda07) August 7, 2025
Verity Townsend is a Japan-based freelance writer who previously served as editor, contributor and translator for the game news site Automaton West. She has also written about Japanese culture and movies for various publications.
