Kolo'ofai left Dunedin this week to join the Coca-Cola club, in Fukuoka, on a two-year contract.
The strapping second-rower from the Southern club played 21 games for Otago between 2004 and 2008.
His best season was in 2007, when he started eight games in the Air New Zealand Cup, but last year he started just one.
Kolo'ofai had a compelling mix of strength and skills but he found himself falling down the rankings in Otago, with Tom Donnelly and Ross Kennedy the favoured lock pairing, Hayden Triggs signing from Manawatu, and University A's Josh Townsend also gaining a contract.
Southern manager Mike Reggett said Kolo'ofai kept the club informed of his plans but did not want a fuss made over his departure.
Reggett said Kolo'ofai, who played more than 100 games for the Magpies, spoke to the team last week and said he felt his career needed a change of scenery.
It was expected Kolo'ofai would have been loaned to Southland later this year had he stayed in New Zealand.
The Coca-Cola club won promotion into Japan's top league of 14 teams at the end of the 2005-06 season.
The squad includes former Chiefs midfield back Mark Ranby, former Hurricanes and University A lock Luke Andrews and former Chiefs flanker Wayne Ormond.
