Beppu - Jack Goodhue calls it "tough love", the intense competition among the four All Blacks centres who have found a way to stay best friends while battling each other for a place in the starting line-up.
Sonny Bill Williams calls it being honest with each other when they put their competitiveness aside to analyse each other's performance in Tests and training.
Williams has long been an All Black star but now, after 54 Tests and at his third World Cup, the 34-year-old's place in the starting XV is no longer guaranteed.
He is likely to start with Goodhue, the baby of the quartet at 24, in Wednesday's World Cup match against Canada after Ryan Crotty and Anton Lienert-Brown patrolled the midfield in their Pool B opener against South Africa.
But all four are battling to be in that starting centre partnership when the tournament gets to the crucial knockout stage.
Backs coach Ian Foster says he knows his preferred pairing but is not revealing anything just yet as the foursome go head-to-head in a contest to fill the two starting berths without creating friction.
While the competition is strong, Williams said they clear the air by making a point of getting together once a week to chat about anything but rugby.
"We talk about things outside footy rather than what's on the field," said Williams, who considers himself "more relaxed" after featuring twice in a World Cup-winning side, while his three midfield rivals are at their first global showpiece.
If the conversation does swing towards upcoming selections, "we're pretty honest" with each other, added Williams.
"We all want to start but we're honest in saying that whoever starts, the other guys are pushing them and preparing them."
Since Ma'a Nonu and Conrad Smith retired from Test rugby at the last World Cup after a phenomenal 62 Tests together, the All Blacks have lacked a consistent midfield pairing.
Starting combinations have included Crotty and Lienert-Brown (nine Tests), Williams and Crotty (12), Crotty and Goodhue (two), Williams and Lienert-Brown (five), Lienert-Brown and Goodhue (one), Williams and Goodhue (three).
Goodhue, who burst on to the international scene last year after partnering Crotty in Super Rugby champion side Canterbury Crusaders, said there was no denying the rivalry at training.
"When we're doing fitness we always try and win but that just drives the standard," he said.
"Training can be a bit of tough love but that's only just to raise our standards, give each other critical feedback and put pressure on each other's skill-sets.
"But we leave it all out on the training field and we're best of friends off the field."
Foster considers it beneficial to have four players striving to fill two slots but said it made selection all the tougher.
"There's two disappointed, one very disappointed and one a little disappointed. They're grown men and that's the nature of the game and they've got to accept the decisions."