World Cup-winning flyhalf legend Dan Carter has tipped Japan to go through the Pool stages of the World Cup and reach the knockout stages next year - and warned favourites New Zealand will not have it all their own way.
The 36-year-old fly-half, who confirmed his stint in Japan would bring an end to glittering career, said the Brave Blossoms were capable of reaching the quarter-finals.
"There is going to have to be a couple of upsets for Japan to make that but they are capable of it," said the three-time world player of the year.
"They've got the team, the players, the coaching staff to pull off these upsets and I'd love to see them in the play-off stages of the next World Cup."
"Not many teams are able to score five tries against the All Blacks. So the Japanese team should be very proud of that," said Carter.
Although, the All Blacks are favourites to lift their third successive Webb Ellis Cup, Carter said the form book does not count for everything.
"Just because you're the number one side in the world doesn't guarantee you're going to win the Rugby World Cup," he said, adding that a lot of teams were peaking ahead of next year's tournament.
"So, I'd like to think the All Blacks will win, but you're never 100 percent sure of that."
Carter was world player of the year in 2005, 2012 and 2015, amassing a world-record 1 598 points in 112 Tests, and is the biggest draw in Japan's domestic league after completing a three-year spell with French side Racing 92.