The G1 Tenno Sho Autumn, considered as one of the most prestigious 2000m events in Japan, is a traditional showcase for older horses but this year has attracted the top three-year-old Isla Bonita.

Winner of this year’s G1 Satsuki Sho (Japanese 2000 Guineas), and runner-up in the G1 Japanese Derby, Isla Bonita was taken off the classic path and sent to the Tenno Sho Autumn, instead of the G1 Kikuka Sho (Japanese St Leger), the final leg of the Japanese Triple Crown.

The unusual move has fans wondering if the colt can become the first three-year-old to capture the race since Symboli Kris S in 2002 when run at Nakayama.

Wagering in Japan is expected to focus on four horses with Isla Bonita, Fenomeno, Gentildonna and Epiphaneia the popular choices.

Champion mare Gentildonna is coming off a layoff and many believe her sights are set on the G1 Japan Cup.

On the other hand Isla Bonita, a son of Fuji Kiseki, started his fall campaign with a win in the G2 St. Lite Kinen (2200m) last month.

He has six wins and two seconds from eight starts and five of his starts have been at Tokyo where he has bagged four wins. His sole defeat at Tokyo was a three-quarter length second in the G1 Japanese Derby in June.

Jockey Christophe Lemaire has the ride and put the colt through his paces on Wednesday at the Miho Training Centre north of Tokyo.

Isla Bonita clocked 67.2 seconds over five furlongs on the woodchip course with no urging.

Fenomeno, a five-year-old by Stay Gold, is coming off back-to-back victories in the the G1 Tenno Sho Spring (3200m). Second in this race in 2012, he returned from a nine-month layoff for a fifth in the G2 Nikkei Sho in March before he notched a win in the Tenno Sho Spring in May.

Despite this Sunday’s event being his first race appearance in six months, he looks sharp in morning work at Miho Training Centre.

Yoshinori Saito, assistant for trainer Hirofumi Toda, said “Last week jockey Masayoshi Ebina gave him a good workout. And this week, the horse really ran as we wanted him to, without losing any concentration until the end.

“It was a good workout. He wasn’t agitated and he looked to be switched on to just the right degree.”

Gentildonna has finished sixth in the G2 Kyoto Kinen and ninth in the G1 Takarazuka Kinen in her two domestic outings this year, both sides of a victory in the G1 Dubai Sheema Classic at Meydan.

Miho-based jockey Keita Tosaki has made the trip to Ritto for some serious work in the last two weeks, putting in runs up the hill course.

Trainer Sei Ishizaka said after this week’s work, “Until this week we’ve worked her hard and all have gone well. She has changed in a good way,” Ishizaka said.

“She can sense that the race is near and she feels on her game now.”

With three wins and a second from her Tokyo bids, all of them at the G1 level, Gentildonna is still a force to be reckoned.

The other big name is the 4-year-old Epiphaneia, who finished fourth to Designs On Rome in the G1 Audemars Piguet QEII Cup at Sha Tin in April.

Epiphaneia has proved reliable coming off a layoff, with his previous starts after spells having brought him a fourth, a win and a third.

He has had only one run at Tokyo (second to Kizuna in last year’s Derby) and is experienced at the distance.

His five starts over 2000m have brought him two wins, one second and one third.