A few have tried and for brief periods made it seem possible. Troy Flavell left New Zealand in 2004 for Japan, came home in 2006, earned seven test caps but then failed to make the World Cup squad. He never really looked the commanding presence of old when he came home - athletic and aerobic as always, just not accurate or high impact enough for the top level.
Luke McAlister famously left for Manchester when he was just 24 and returned at 26. He was immediately restored to the All Blacks in 2009 which proved to be a mistake. He really wasn't the same player - and his selection was purely about justifying the decision to bring him home on a significant contract.
Maybe Kaino will be the first to prove it is possible, but no one should be expectant. The first barrier to be overcome is financial. Kaino is believed to have signed with Toyota for $1.3m a season. That contract will finish in February/March 2014 at which point he'll be nearly 31. If he wanted to come home then, he'd have to be prepared to take a huge pay cut.
Despite his test experience, world-class performances and unstinting hard work, a 31-year-old flanker who has put himself about and been away from New Zealand for two years, is not going to attract top dollar. He would face a massive pay cut - probably about $1m a year, if not more.
If he stays injury-free and delivers for Toyota, they would no doubt be keen to keep him on similar money to his just-signed deal and there would be a handful of European clubs willing to buy him for considerably more than he could earn by coming home.
Then there is the question of whether he'd physically still be up to it. His body has been pounded over the years, so there is one school of thought that two seasons in the shorter, sharper Japanese season where the physicality is nowhere near the level of Super Rugby or tests, may restore Kaino's body and mental zest for top flight action. It may add another couple of years onto his career.
But the price of moving to Japan is the quality of rugby and even a great player like Kaino may find it hard to be out of Super Rugby for two years and then assimilate.
The intensity just isn't the same.By 2014 there could be an angry, rampaging Brad Shields playing blindside for the All Blacks, with Luke Whitelock not far behind and Adam Thomson still going strong.
The road back to the All Blacks for Kaino is likely to be long, demanding and poorly paid in comparison.
It's best to consider Kaino's test career over.
He probably won't be coming back.