Sodashi won the Victoria Mile on Sunday with a closing rally and received an especially loud roar from the fans at Tokyo Racecourse. The cheers did not come exclusively from those who had bet her to win at 5-1. The filly has become a sensation in Japanese horse racing circles because of her color: pure white.

White thoroughbred horses are exceedingly rare: As few as one in 100,000 are considered pure white. To qualify, the horse’s entire coat must be white and cannot have any other colors. Sodashi meets that definition.

Other light-colored horses that you might see at the track are registered as gray (a mixture of black and white hairs) or roan (red or brown and white). Some of these may become whiter as they grow older but still don’t qualify as the rare white horse.

Plenty of gray and roan horses have fared well over the years, including Kentucky Derby winners like Spectacular Bid in 1979, Winning Colors in 1988 and Silver Charm in 1997. But the handful of white horses hadn’t really distinguished themselves until Sodashi came along.

Sodashi is the first white horse in Japan to win a Group One race and, with white horses in other nations just as rare, would have to be considered the best ever of her color.

Recent research has shown that white horses are the product of spontaneous gene mutations. Some of those mutations are dominant, so horses can potentially pass on the white color no matter whom they are mated with.

Sodashi’s sire, Kurofune, was gray. But the key to her color is undoubtedly found on her mother’s side. Her dam, Buchiko, was striking in her own way, white with chestnut-colored spots. Her dam’s dam, Shirayukihime, was, like her granddaughter, pure white. (Shirayukihime translates as “snow white.”)

Sodashi first gained attention with a streak of five straight wins in 2020 and 2021 that included the Japanese 1000 Guineas. But she then had a bad run of form until a return to her best on Sunday. Her exploits have earned her the nickname the White Wonder.

The sight of the snow-white Sodashi dashing through the field had a cinematic quality. The impression was amplified by the jockey Hayato Yoshida’s unusual all-white bridle.

“As today’s race included a very strong field, it was like a dream for a white horse to be able to win a Group One race at Tokyo Racecourse,” Yoshida told Japan Racing.

The win qualifies the 4-year-old Sodashi to run in the Breeders’ Cup Filly & Mare Turf in early November at Keeneland in Lexington, Ky., as well as two big French races in August and September. It’s not clear whether she will participate: Her trainer Naosuke Sugai has not yet made a decision on any international travel for the filly. Wherever she goes, she will no doubt make a startling visual impression.