She was sired by the Japanese Triple Crown winner Deep Impact out of the British mare Donna Blini, who won the Group One Cheveley Park Stakes in 2005.
Gentildonna began her three-year-old season by winning the Grade 3 Shinzan Kinen against male horses over one mile at Kyoto in January and then finished fourth to Hana's Goal in the Tulip Sho at Hanshin Racecourse in March.
At Kyoto on 14 October, Gentildonna completed the Triple Crown and defeated Verxina for the fourth time in a row when prevailing by a nose in the Shuka Sho.
There was a protest made for interference by the connections of Orfevre, and Gentildonna had to wait 20 long minutes until her triumph was confirmed, at the cost of subsequent 2-day suspension to Iwata.
[4] On 30 March Gentildonna raced outside Japan for the first time when she started the 11/8 favourite for the Dubai Sheema Classic but was beaten two and a quarter lengths by the Irish six-year-old St Nicholas Abbey.
After three consecutive defeats, Yasunari Iwata lost the ride on Gentildonna, and when the filly appeared to defend the Japan Cup on 24 November, she was ridden by the British jockey Ryan Moore who had received a temporary contract from the JRA.
The race was run at a slow pace, and Moore positioned Gentildonna just behind the leaders before accelerating through a gap on the inside to take the lead in the straight.
[8] On her return to Japan, the mare again contested the Takarazuka Kinen at Hanshin Racecourse but finished seventh of the twelve runners, seven and a half lengths behind the winner Gold Ship.
After a four-month summer break, Gentildonna returned to contest Japan's three most important autumn races, beginning with the Tenno Sho on 2 November.
Ridden for the first time by Keita Tosaki she finished second of the eighteen runners, beaten three quarters of a length Spielberg with the favourite Isla Bonita taking third ahead of the unusually named Love Is Boo Shet.
The Arima Kinen over 2500 metres at Nakayama Racecourse on 28 December attracted its customary strong field, and Gentildonna started fourth in the betting behind Gold Ship, Epiphaneia and Just A Way with the other contenders including Denim And Ruby, One And Only (Tokyo Yushun), Meisho Mambo, Fenomeno and Verxina.
She gained the advantage and held off several late challenges to win by three quarters of a length from the three-year-old colt To The World, with Gold Ship, Just A Way, Epiphaneia, Lachesis and Last Impact close behind.