The Japanese horses confirmed are Isla Bonita (trainer Hironori Kurita), Logotype (Tsuyoshi Tanaka), Tosen Stardom and Tosen Reve, both trained by Yasutoshi Ikee.

Racing NSW chief executive Peter V'landys described Isla Bonita as "one of the best horses in Japan".

"He won their 2000 Guineas before placing second in the Japanese Derby as a three-year-old and was crowned champion three-year-old colt of Japan in 2014," he said.

"In his past two starts Isla Bonita has finished third in the Tenno Sho (Autumn) and Japanese Mile Championship."

Logotype is a dual Group One winner targeting the $3 million The Star Doncaster Mile.

"Logotype was the champion two-year-old of his year in Japan and as a three-year-old defeated the champion racehorse Epiphaneia," Mr V'landys said.

Tosen Stardom returns to Sydney for the $4m Longines Queen Elizabeth Stakes having finished fifth in 2015, a run which followed a second in the Group 1 Ranvet Stakes at Rosehill Gardens.

Stablemate Tosen Reve may become the first Japanese runner in a Sydney Cup, with trainer Yasutoshi Ikee targeting either the $2m race or Queen Elizabeth Stakes after the horse's recent strong form.

"We are delighted to welcome horses from Japan back to Sydney for The Championships, bringing with them such strong form," Australian Turf Club CEO Darren Pearce said.

"I am sure they would have learned a great deal from last year and will again prove hard to beat in any race they contest."

The Japanese runners will again be accommodated at the Sydney Quarantine Centre at Canterbury Park Racecourse.

"Japanese horses provided a key part of The Championships puzzle in 2015 and these four horses will again create tremendous interest at Royal Randwick in April," Mr V'landys said.

A record 1289 nominations were received for the 10 races of The Championships at Royal Randwick on April 2 and 9.

Total nominations for The Championships are up by 68 on 2015, an increase of nearly 6 per cent. The feature race, the $4m Group 1 Longines Queen Elizabeth Stakes over 2000m on Day 2, attracted 96 nominations. There are 162 nominations for the $3 million The Star Doncaster Mile (1600m) on the opening day 23 more than last year.

*This preview of The Championships brought to you by Racing NSW. Mark Brassel writes for Racing NSW Magazine and thechampionships.com.au.