The meeting took place as the Tiopira family made their way back to Auckland, where they have been living while Stevie Ray gets treatment.
Stevie Ray said it was awesome to meet Fisiihoi, and thanked him for the bag of Chiefs merchandise, including a flag and a rugby ball.
Mr and Mrs Tiopira said the visit had lifted their son's spirits.
"The last couple of weeks he's been quite down, thank you for the gifts."
Fisiihoi said he was happy to help out in such a "heartbreaking situation".
"[The Chiefs] get out into the community, it's a big part of what we do. We try to help out in these situations, and put a smile on their faces."
Mrs Tiopira said it has been a very emotional few days in Kawerau.
"It was our first trip home since Stevie Ray was diagnosed in November."
On their return to Kawerau, Stevie Ray, an avid reader, asked first to visit the library where he "had lived, and just came home to sleep", Mrs Tiopira said.
Then he was taken to visit his school and friends for a "bit of normalcy".
"It was an emotional send-off. They did a haka for him ... all lovely kids," Mrs Tiopira said.
Through the Child Cancer Foundation, the family has had a support co-ordinator in Auckland who has helped the family immensely.
Mrs Tiopira said she had helped her come to terms with the situation and explained a lot of the medical terms.
Mr Tiopira said they have set up an online fundraising page on Givealittle to raise money for a wheelchair-accessible van, with secondhand vans costing around $25,000.
They had been blown away by people's generosity during a hard time, he said.
"People have been so amazing, even people we don't know donating to the page."
To donate please visit givealittle.co.nz/cause/help4stevie-ray.