A brown horse with a stocking on his right back leg and a wide blaze marking.
He gained fame, initially, for coming in second place for both the Satsuki-sho (to Geoglyph) and the Tokyo Yushun (to Do Deuce), before turning to the 2022 Autumn Tenno-sho, where he covered and overtook runner Panthalassa's 15 to 20 lengths lead, earning him his first GI title. Equinox then went on to win the 2022 Arima Kinen as well as the 2023 Dubai Sheema Classic in his overseas stint. Afterwards, he won the 2023 Takarazuka Kinen by a neck, almost losing to Through Seven Seas due to a fumble. He finished his streak by shattering the race record (and the world record on 2000m turf) at the 2023 Autumn Tenno-sho and dominating a very stacked 2023 Japan Cup. He was retired to stud afterwards, citing he would not have been ready in time for the Arima Kinen.
He is Kitasan Black's first G1-winning progeny and proved himself to be not only one of the best racehorses of his generation but also becoming the best rated racehorse in the world. His victory at the 2023 Japan Cup made him Japan's greatest earning racehorse and, had he continued, he would have been well on his way to become Japan's first 7 G1 winner on turf with no classic race wins.
In the context of Umamusume, as the son of Kitasan Black, most fan designs portray him in some form of Japanese-style outfit, often with a Sun & Moon motif with a red and blue color scheme that references the racing colors of Silk Racing, Equinox's owner.