When Kieran Read, captain of New Zealand’s national rugby team, announced in March that he would soon leave to play for a little-known rugby club in Japan, it sent shockwaves through the sport’s most successful nation.

His body beaten up from years competing at the pinnacle of professional rugby, the 33-year-old will play for Toyota Verblitz in Japan later this year. That means he can no longer play for New Zealand’s national team, the All Blacks, because of a rule that bars foreign-based players from representing the country. And Read is far from the only player making that choice.

Lured by pay that the country’s clubs and franchises cannot match, and a growing financial crisis afflicting rugby at home, New Zealand’s top national players are leaving in unprecedented numbers for Japanese clubs, giving up careers with the national team in the process. Many plan to quit after the All Blacks try to defend their 2015 Rugby World Cup win at the 2019 edition, which starts in September. New Zealand has won an unmatched three World Cups. The ultimate irony? The 2019 edition is being held in Japan, the first time a nation that’s not a rugby powerhouse is hosting the tournament.

On average, New Zealand players would earn at least double [in Japan]. Steve Jackson, University of Otago

All Blacks legends Ryan Crotty and Brodie Retallick are joining Read in Japan. Other regular first-team starters such as Liam Squire, Jackson Hemopo and Sam Whitelock have signed contracts to play in Japan in 2020. Even national head coach Steve Hansen is rumored to be headed to Japan in pursuit of a lucrative payday. It’s an exodus that threatens to dramatically strip New Zealand of some of its best rugby resources — placing its legacy on the line.

“On average, New Zealand players would earn at least double what they earn in New Zealand … and the season is shorter,” says Steve Jackson, a professor at the University of Otago who specializes in the socio-cultural aspects of sports.

Steve Tew, CEO of Rugby New Zealand, conceded the growing headache for the country in a radio interview earlier this year. The attraction of Japan, he said, is causing New Zealand “a little bit more trouble with some of the guys [than] we would prefer.”

To be sure, rugby players from New Zealand have in the past plied their trade in physically demanding leagues in France and England, where, like Japan, salaries can be several times the going rate of New Zealand’s. But barring isolated instances, those players weren’t part of the national side. What’s different with Japan is that it’s the All Blacks star players — their captain no less — who are leaving.

For Japan, rugby represents an economic opportunity in a region where it’s a major sport. The Rugby World Cup alone, which runs through November, is expected to add $2 billion to the country’s economy. It’s also a smart branding option for Japanese firms with a regional and global presence. Giants such as Toyota, Toshiba and Panasonic all own or sponsor club teams participating in the country’s Top League and are behind the lucrative contracts drawing foreign players.

Dan Carter, a star of the 2015 World Cup win who now plays in Japan, is said to have a salary of $1.33 million. By comparison, Read earns an estimated $670,000 through his current contract in New Zealand. In Japan, a country of 127 million people, the potential for star names to win major endorsement deals with sports and other companies is significant. For younger players too, Japan represents opportunities that New Zealand can’t match. Players competing in the lower of New Zealand’s two professional leagues start at about $40,000 a year; in Japan, they’re estimated to be able to earn up to $180,000.

That’s why, in addition to current All Blacks stars, Japan is beginning to attract upcoming New Zealand players. Japan’s Sunwolves franchise alone counts 19 New Zealand players among its ranks. Experts estimate at least 10 former All Blacks players from a total of 110 New Zealanders have decamped to Japan. One New Zealand club, the Dunedin-based Highlanders, is set to lose seven players, including three All Blacks, to Japan this year alone.

The same month Read made his announcement, 25-year-old Pasqualle Dunn from Auckland, who plays inside center, landed in Japan to join the Osaka-based Kintetsu Liners on a two-year contract. “There are at least six of my friends from home here now, and more are coming [to play rugby],” he says, adding that his salary now is multiple times what he could expect to earn in New Zealand.

Because Japan’s league is still less competitive than those in the U.K. or France, younger players like Dunn have greater opportunities there. And for established All Blacks stars, many in their 30s, Japan offers a chance to mint money without play that’ll tax their aging limbs the way European leagues would. That’s even more so for those like Read who are in the latter part of their careers. Unlike France or England, where players are contracted for as many as 35 grueling games per season, in Japan, the season typically lasts just 10 games. “Training and games are less physical, so it is not as hard on the body, and this matters when you are older and trying to prolong your career,” says Jackson.

Some players simply fall in love with Japan. “Japan is like no other place in the world,” says retired rugby player Marty Veale, who played for the Kubota Spears in Funabashi until 2008. “For me to get to experience it through the game I grew up playing … it was incredible.”

It’s hard to blame players for the defection. Concussions and bone-breaking tackles are a major aspect of the modern game and players are under increasing pressure to manage their game time and bodies so as to play longer while securing higher-paying contracts.

Meanwhile, Rugby New Zealand is struggling for a fix to the growing crisis. It could lift its rule preventing foreign-based players from playing for the national team. That would make the current generation of players headed to Japan eligible for the All Blacks jersey. But many fear that would only further open the floodgates for New Zealand’s upcoming stars to play abroad, destroying the dizzyingly high standards of club and local rugby, which routinely produce players who combine raw strength and breathtaking skill like nowhere else. Instead, New Zealand is trying to cut its losses. Because players in Japan are less likely to be injured if they do return to New Zealand, clubs in the two countries have begun to establish ties.

Indeed, the fear of losing the national jersey still remains a deterrent to some. Whitelock, for instance, will play in Japan for part of 2020 but then return to New Zealand in time for national games.

Matching the salaries that Japanese clubs offer is next to impossible for New Zealand, one of the smallest economies among major rugby-playing nations. As it is, Rugby New Zealand registered losses worth $1.2 million last year. Analysts have begun to warn of falling participation at the school level, and its damaging consequences down the road.

Despite those challenges, the All Blacks remain red-hot favorites for the World Cup in Japan. But this time, there’s more than a trophy on the line. How they perform could determine what a future generation of New Zealand rugby players will value more: a shot at glory in the All Blacks jersey, or a safer, wealthier career in Japan.