The Chiefs have lost Tom Marshall, Bryce Heem and Hosea Gear from their 2015 roster so this is a timely boost with Fisiiahi an option for either wing or fullback alongside other outsides such as Toni Pulu and James Lowe and the McKenzie brothers.
Fisiiahi has been in Hamilton to check out the Chiefs' set-up and likes what he has seen.
"The gym is not as flash as the Warriors', but it's got everything you need. The staff and players are very welcoming and they showed me around Hamilton too," he said.
Chiefs coach Dave Rennie said: "Glen is a great addition to our group. In the mould of Asaeli Tikoirotuma, he is electric, has a strong skill set and is an outstanding support player. The opportunity to roam on both sides of the park in our game will suit him."
The Chiefs have 28 players signed for 2016, with just four spots still to fill, and have been very proactive in signing or re-signing players in recent weeks. By contrast, the Blues have been conspicuous by their silence, with 12 spots to fill, though that will surely change in the coming weeks.
Fisiiahi spoke to other converts, including former Warriors Under-20s player Ngataua Hukutai, in the Counties Manukau squad, but a chat with Wallaby fullback Israel Folau, one of the most successful league to rugby converts, gave him a boost.
"He said it's a switch he's never regretted.
"Words like that from a high profile player definitely give you confidence when you are switching codes."
Fisiiahi's rugby background is solid and goes back to his Wesley College days in the heart of Chiefs and Counties Manukau territory. He has also signed with the Steelers for the 2016 ITM Cup. But in 2008 he played first-five for the First XV outside Augustine Pulu. Charlie Piutau was on the wing. That team won yet another Counties Manukau championship, until they fell to a powerful Hamilton Boys' High combination which included Tawera Kerr-Barlow and Declan O'Donnell. Fisiiahi also wore the Counties Manukau Under-18 colours that season.
"Seeing how far August and Charlie have gone in their careers got me thinking about how far I could go," he added.
Glen Fisiiahi
Born: December 2, 1990.
Rugby honours: Wesley College First XV (Counties champion), school sports dux, Counties Manukau Under-18s (2008).
League/NRL career: Junior Warriors (2009), Junior Kiwis (2010), first grade debut (2011), three tests for Tonga (2013).