Keita Tosaki is no stranger to high-pressure decisions, but few have carried the emotional and public weight of the one he’s made for Sunday’s G1 Arima Kinen at Nakayama.

Japan’s perennial leading jockey has opted to ride Danon Decile in the JPY1.09 billion year-end showpiece, turning away from reigning champion Regaleira despite being closely associated with the mare throughout her recent career peak.

Tosaki partnered Regaleira in her last four starts, including her victory in the 2024 Arima Kinen, yet will now attempt to prevent her from becoming the first mare in history to win the race in back-to-back years. The choice is amplified by the unique nature of the Arima Kinen, with the field partially decided by fan vote. Regaleira dominated that ballot, attracting a record-breaking 612,771 votes as the horse Japanese fans most wanted to see in the finale of the season.

With Tosaki switching allegiances, the ride on Regaleira passes to Christophe Lemaire, setting up one of the most talked-about jockey storylines of the year. Tosaki has been candid about the reaction his decision has drawn.

“Most people say, 'You're not riding Regaleira?' To be honest, it's a tough call. You do find yourself wishing that when you wake up tomorrow morning your body might somehow have split into two. Being able to agonise over a choice like this at this level is a luxury, though,” he said.

“I try not to be too aware of her. She got over 600,000 fan votes, right? I do feel like I've really let her fans down. Even so, the way (Danon) ‘Decile’ ran in Dubai is something I'll never forget in my riding career.”

Danon Decile brings elite international credentials into Sunday’s 2500-meter test. The son of Epiphaneia captured the 2024 Japanese Derby before stamping himself as a global force with victory in the 2025 Dubai Sheema Classic at Meydan. Tosaki believes those performances reveal a ceiling still not fully explored.

“I've always thought he's a horse with a huge amount of ability. I rode against him in the (2024) Derby on Justin Milano and I could really feel how strong he was.

“Then when I got the chance to ride him in Dubai, in the Sheema Classic, the power he showed there was just incredible.”

The matchup has history. Danon Decile finished third behind Regaleira in last year’s Arima Kinen, and the mare has arguably improved again since then, most notably when routing a high-class field in the G1 Queen Elizabeth II Cup at Kyoto in November.

Beyond the headline duel, the 2025 edition is deep with proven Group 1 performers. Museum Mile, winner of the G1 Satsuki Sho and runner-up in the Tenno Sho Autumn, returns under Cristian Demuro seeking a second top-level success. Justin Palace, Shin Emperor and Mystery Way all bring strong staying profiles, while Tastiera — the 2023 Japanese Derby hero and recent Hong Kong Group 1 winner — is expected to make his final start before retirement to stud.

Admire Terra and Meisho Tabaru complete a field that underscores why the Arima Kinen remains Japan’s most emotionally charged and commercially powerful race — a fitting stage for a decision that has already defined its narrative before the gates even open.