[7] Do Deuce's dam Dust And Diamonds was bred in Kentucky and raced with considerable success in the United States where she won the Gallant Bloom Handicap and ran second in the Breeders' Cup Filly & Mare Sprint.

[9] Do Deuce began his racing career in a contest for previously unraced juveniles over 1800 metres on good to firm ground at Kokura Racecourse on 5 September 2021.

Take was again in the saddle when the colt was stepped up in class to contest the Listed Ivy Stakes over the same distance at Tokyo Racecourse in the following month.

He started second choice in the betting and prevailed by a neck and three quarters of a length from Gran Cielo and Ask Victor More after taking the lead in the straight.

[12] In the official Japanese rankings Do Deuce was rated the best two-year-old of 2021, one pound ahead of Serifos and the Hopeful Stakes winner Killer Ability.

He tracked the leaders for most of the way and finished strongly but sustained his first defeat as he failed to run down Ask Victor More and was beaten a neck into second place.

He made relentless progress in the straight, overhauled the leader Ask Victor More 150 metres from the finish and held off the late challenge of Equinox to win by a neck.

However, Do Deuce finished at 7th in that race, with his usual jockey being injured as a result of being kicked by another horse that day and instead ridden by Keita Tosaki [ja], who was a last minute replacement.

[25][26] Tosaki would reprise his role as Do Deuce's jockey in the following Japan Cup, as Take was still recovering from his injuries at the time,[27] but finished fourth behind Equinox.

[29][30] After the Arima Kinen; Take, Tomomichi, and Matsushima (head of Kieffers) expressed their desires to return to Dubai and France once again.