Organisers said the Rugby World Cup was set to break broadcast records and grow the game in Asia as excitement builds in Japan, with huge crowds turning out for training sessions ahead of Friday's kick-off.
World Rugby said 96 percent of tickets had been sold and that the curtain-raiser between Japan and Russia could set a tournament record for viewing figures in a single country.
The World Cup, the first to be held in Asia, is taking place eight years after the devastating Fukushima earthquake, tsunami and nuclear disaster, and comes just a year before Tokyo hosts the 2020 Olympics.
"Earthquakes, floods, we suffered many hardships," organising committee chairman Fujio Mitarai told reporters on Tuesday.
World Rugby CEO Brett Gosper said the tournament's commercial revenues will outstrip the 2015 edition in England and Wales, adding that the competition was on course to be a sell-out.
"It's going to be a very different World Cup than the others," Gosper told AFP.
"We've already seen the passion of the supporters who are coming to the training sessions, 15,000 people at yesterday's training session with the Welsh. This tournament is going to be full of surprises on the pitch and off it.
"The goal is to develop the sport and get young people watching it. We set ourselves the objective of having one million new participants, we're at 1.8 million before the tournament in Japan and in Asia."
Tough competition between the teams, with the top world ranking changing hands three times in recent weeks, has piqued anticipation as the tournament has no clear favourite.
"After 10 years of meticulous preparation, the waiting is over," said World Rugby chairman Bill Beaumont. "This tournament will accelerate rugby's global reach.