Growing up in a strict methodist household, Fai life revolved around school and church until one day he asked his mother if he could borrow $20.
When he returned the 12-year-old told his mum he'd just signed up to play for the Mangere East Hawks. A few years later his talent was so obvious he'd signed a development contract with the Warriors.
But at age 20, Fai - who seemed to have the league world at his feet - tragically died off the coastline of Auckland's Bethells Beach as he attempted to save himself and his brother Gillesbie from a rip.
Gillesbie survived and recently sat down with the Herald to tell his story for the three-part podcast and extended feature The Remarkable Life and Tragic Death of Sonny Fai, which is released today.
The podcast series can be accessed via iTunes, iHeartRadio and the Herald website.
Gillesbie - who prefers to go by Lesi - recalled the tragic death by saying: "It was just a normal Sunday. We weren't doing much and then Sonny brought up going to the beach.
"We were just like, 'Oh yeah, let's go' and a few of our cousins went along as well."
Tragically, hours later and Sonny Fai - who is remembered as one of the best local talents to have come through the Warriors' pathways since their inception into the NRL in 1995 - was dead.
As well as Lesi opening up on the tragic death of his brother - and how it continues to impact him - the Herald presentation also features interviews with the Fai family, with key Warriors staff from the time and from those who knew him when he was a ever-smiling teen pulling on a Mangere East Hawks jumper.
"He was mainly into church. We were full-time Christians going hard into church so there was barely any time for sport," said his sister Lalelei Fai Tupulua.
"He just came home one day… and said to mum, 'Oh I need 20 bucks [and] my birth certificate. He just ran out of the house, he didn't say anything, and he came back an hour or so later and just said, 'I've just registered for rugby league and I'm going to start playing next week'."
Because the family spent their weekends with church activities, the parents and siblings rarely saw Sonny play.
It was Lalelei's husband, Tupulua Tupulua who first figured out he had talent beyond the ordinary.
"We went to watch him and my husband said to me, 'I think he's really good'."
Fai Tupulua convinced her parents to come and watch him and pretty soon they had potential player managers sweet talking them in the hope Sonny would sign with them.
His career skyrocketed then, but not before one huge scare.
After one under-15s match, Fai collapsed and his body began to shut down.
Mangere East president Peter Sykes takes up the story.
"He wasn't himself. He was pretty sort of fluid, fun-loving player but this time he was really unfocused, cold, shaky. He played the game with all his guts but not up to his usual energy and at the end of the game he basically collapsed," Sykes said.
"We had to wrap him up, find blankets and bundled him off to [Middlemore] hospital."
Sykes said it was touch and go at the time as the fever attacked his body and took a long time to control.