While the flurry of signings can be partly explained by Japan's rigid contracting period, there is no doubt the country is attracting more New Zealand players and, significantly, they are no longer at the end of their careers.
The relative proximity of Japan to New Zealand, the favourable exchange rate, friendly visa conditions, time zone and less physical nature of the competition means the country is leaping ahead of Europe as the major threat to the New Zealand Rugby Union. It is understood that a junior All Black can earn up to $600,000 a season in Japan, almost three times more than in New Zealand.
Chiefs centre Richard Kahui (Toshiba) and wing Lelia Masaga (Honda) recently announced their moves, with the former a shoo-in to make the All Blacks squad this year had he not chosen to move.
The NZRU has long conceded it cannot match the financial clout of overseas clubs and relies on the black jersey for its pulling power.
"Statistically there are probably fewer players going overseas, but what we are seeing is, in regards to Japan and what was traditionally seen as a retirement village, people are going up there in their pomp and much younger than they have in the past. That is creating visibility because they're higher-profile guys," said Simon Porter, a player agent for the Essentially group.
That was a trend also seen by Esportif agent and former All Black Craig Innes, who represents Boric. "There's more of that top echelon of player choosing to head for Japan," he said. "They've become trailblazers for the others."
Innes also represents former All Blacks enforcer Jerome Kaino, a blindside flanker coach Steve Hansen has struggled to replace in his current line-up. Kaino was one of the first of New Zealand's high-profile players to leave for Japan after the World Cup.
Also leaving then were Ma'a Nonu (on a short-term contract) and Brad Thorn, both back playing for the Highlanders. Former All Blacks and Chiefs midfielder Sonny Bill Williams spent a short but lucrative stint at Panasonic.
All Blacks first-five Dan Carter has ruled out playing in France during his sabbatical next year because of the physicality of the rugby there, but Japan remains a likely option.
"Most of the guys who go up there, it takes them a good year to find their feet," said Innes. "It's a different culture to what we're used to in New Zealand - the food and language - most of them do like the lifestyle. Most of the feedback is positive.
"The physical aspect is a lot different to New Zealand or Europe but... they train like crazy in Japan. By our standards they overtrain something terrible."
The feeling is that Japan is less volatile than Europe, where players can be at the mercy of owners' largesse and financial viability.
In Japan, corporates hire foreign players as employees and they take part in an amateur competition.
The big OE
Those signed with overseas clubs since the World Cup
Japan:
• Anthony Boric (Mitsubishi)
• Stephen Donald (Bath, now Mitsubishi)
• Ben May (Sanix)
• Richard Kahui (Toshiba)
• Lelia Masaga (Honda)
• Isaia Toeava (Canon)
• Sonny Bill Williams (Panasonic)
• Adam Thomson (Canon)
• Jerome Kaino (Toyota)
• Ma'a Nonu (Ricoh, now Highlanders)
• Brad Thorn (Sanix, now Highlanders)
• Mils Muliaina (Docomo)
Europe
• John Afoa (Ulster, Ireland)
• Craig Clarke (Connacht, Ireland)
• Jimmy Cowan (Gloucester, England)
• Rene Ranger (Montpellier, France TBC)
• Sean Maitland (Glasgow, Scotland)
