Tamanivalu says the decision to re-sign with the Crusaders was a straight- forward one when he thought about how much he has been enjoying this first year with the team.
"I have been loving playing for this team and learning from the coaches and players around me," he said.
"This has been such a special season for all of us at the Crusaders with so many highlights and great memories, and the best is yet to come.
"There were options to go overseas, but I am not ready to walk away from all of the good stuff here just yet."
Crusaders coach Scott Robertson says Tamanivalu, who played three Tests for the All Blacks against Wales last year, had made important contributions on and off the field.
"Seta came here with a winning attitude and a desire to make an impact on this team, and there's no doubt that he has done that," he said.
"We're excited that we will be able to continue working with his natural talents in 2018."
- NZN