"Rugby is important but family is the reason for everything, so to be able to be based nearer Rotorua and to continue my Super Rugby career in an environment where whanau is No 1and I can keep growing as a player is exciting," Tahuriorangi said.
Cooper said the Chiefs had secured a "great balance of experience and X-factor" with the three signings.
"Having worked with Brad in the Maori All Blacks and with Te Toiroa in Taranaki for the past few years I'm excited, and have a lot of confidence in what they'll bring to the Chiefs in 2018 and beyond.
"I'm really looking forward to working with Jonathan. At just 20 years of age he has a big future ahead of him and will create great competition amongst our three halfbacks for the starting spot."
Tahuriorangi was a key member of the RBHS first XV with his strong performances earning him selection into the Chiefs under-17 squad.
In 2014, he moved to New Plymouth to join the Taranaki Rugby Academy. Impressive performances in 2015 saw him selected for the New Zealand under-20 team and the New Zealand Barbarians. He then made the Taranaki Mitre 10 Cup team, which capped off a stellar year.
Tahuriorangi has spent two seasons at the Hurricanes, starting against the British & Irish Lions, as well as making 10 appearances in Super Rugby to date.
The promising halfback has experience playing under Colin Cooper with Taranaki, as well as being named in the Maori All Blacks squad for the 2017 DHL New Zealand Lions Series.
Dynamic halfback Brad Weber has played 41 Investec Super Rugby games for the Chiefs to date. His 2017 on-field aspirations suffered a set-back when he fractured his femur during this year's inaugural Brisbane Global Rugby Tens final.
He will make his highly anticipated return to rugby for Hawke's Bay in the 2017 Mitre 10 Cup competition.
"The Chiefs gave me my first opportunity as an unknown player four years ago and I'm really looking forward to carrying on playing for this team that I love.
"The culture here is second to none and there's no place I'd rather be as I strive to reach the goals I've set for the next few years," Weber said.
Taumateine said he was excited to continue his rugby journey with the Chiefs.
"It's been a really enjoyable and challenging year for me experiencing my first season of Super Rugby with the Chiefs. I've learned a lot this season and I'm excited to continue learning and growing in the Chiefs environment both as a player and as a person," said Taumateine.