The 30-year-old, 94-test All Black has signed a two-year contract with the Japanese club NTT Docomo from next year.
"Once this season is over it will be time for something different," Muliaina said today.
"Japan itself offers a completely different culture and way of life that my entire family is looking forward to experiencing."
Muliaina joins a growing list of prominent players who are to take their services offshore, with Joe Rokocoko, Neemia Tialata and Brad Thorn, among others, having announced their departures towards the end of this year.
One of the best fullbacks in world rugby, Muliaina made his provincial debut for Auckland in 1999, his Super debut for the Blues in 2001 and his All Blacks debut against England in 2003.
He has been New Zealand's first-choice fullback since then and in 2009 he captained the All Blacks in three tests.
He jointly holds the All Black test caps record of 94 with skipper Richie McCaw.
All Black coach Graham Henry has known Muliaina since he moved from Southland to Auckland as a schoolboy.
"Mils goes to Japan next year with the best wishes of everyone involved in the All Blacks," Henry said.
"He is a special All Black, along with Richie McCaw our most-capped test player, an outstanding footballer who is the best in the world in his position.
"Mils is a natural leader, he has tremendous respect of his peers and has helped considerably in the development of younger players."
