The title instantly jumps out: '$EED or GR€€D? The Book Most Pastors Want You to Read!' It sits at the top of Charles Piutau's book collection in his Belfast apartment, next to 'An Intensive Course in Tongan', and a collection of other books linked to the church.

"I've just started reading it," says Piutau. "It's pretty key for me at the moment."

Piutau was born into a working-class Pacific Island family in Auckland. He was temporarily adopted as a baby and was one of 10 siblings whose bedrooms spilled into the garage of their four-bed home.

Now, in a tale of rags to riches, he is about to become the highest paid player in the world.

"Religious books are my go-to," says rugby's first million-pound man. "Seed or Greed is written by the same guy who wrote 'From the Pit to the Palace', which is about Joseph being sold into slavery by his brothers. It teaches you not to let money and greed overtake who you are. You might want to buy a Ferrari ... but do you actually need it?"

Piutau drives a player-issue car from Ulster's sponsors. At 25, he has sacrificed his career as an All Black to help feed his family.

He will leave Ulster for his record-breaking £1m-a-season contract at Bristol next summer - joining his elder brother, Siale - and has left behind New Zealand, where he graduated from the same Auckland college as Jonah Lomu. A mercenary act? Far from it.

"Every Pacific Island kid is on the same boat," he says. "Some would rather stay back, play X number of Tests and become a great All Black. For me, I came to the conclusion that, man, that wasn't me. My family is going to be with me for ever and they're the people closest to me. Rugby's not for ever and I want to be able to look after my parents.

"They left their friends and family in Tonga to give us a chance to chase our dream. My dad was a bartender, battery company worker, taxi driver. He had all sorts of jobs at the same time to look after us kids. People will have their opinions but they don't know the sacrifices my parents made.

"They gave us the best childhood. It never crossed my mind to think, 'Man, we've got 12 people living in a four-bed house'. We had so much fun: playing games, hiding things on the roof. There was always someone laughing or crying - usually me because my brothers were too big to tackle!"

Life in Belfast is somewhat quieter. Piutau lives by himself in an apartment overlooking the docks. He has been to the local church with Peter Brown, the Ulster lock, and teaches himself guitar in between training sessions.

Besides a drone, which he likes to fly over the harbour from his balcony, his only self-indulgent purchase is a framed pair of boxing gloves signed by Manny Pacquiao.

"I like guys like Pacquiao who go way beyond their sport and have a positive influence on their communities,' he says. 'Obviously the other sportsman I idolised growing up was Jonah.

"Back at school, you saw photos of his jerseys up in the dining room and thought, 'Maybe, one day, mine can be up there too'.

"The teachers would tell us stories about him. It was a boarding school and he had a bed that was specially made for him because he was too big. I saw all his athletic records but I never got close to them. I wore his No 11 jersey ... that was really cool. I would shave an 11 into my eyebrow - two lines - because, apparently, that's what Jonah did."

At Wesley College, Piutau led the school dance troupe. "It sounds funny, but dance was one of the best things I did at high school," he says, before offering a rendition of Justin Bieber's Despacito on his acoustic guitar. "Back then it was cheesy stuff or slow jams for the girls, like Zapp's I Want to be Your Man. We weren't the best but one of my brothers went to the dance world champs.

"For me, it helped with my rugby; footwork, coordination and stuff like that. But the bigger thing was how it forced me to talk in front of people. Islanders grow up in this culture where they respect their elders and never answer back. When they get older, they find it harder to speak out or voice an opinion. They might look at the floor when they're talking and it's misinterpreted as disrespect, but it's the opposite.

"Dance was the start of me becoming a leader."

These days, Piutau dances around opponents with his footwork or smashes through them with his Polynesian power. He is the best winger in the northern hemisphere and, this Friday night, he will be terrorising Wasps - his former club - in the opening round of the Champions Cup.

He is a perfectionist - personally phoning after this interview to clarify his father's jobs - and a model professional, until a half-eaten KFC bucket slips out of the fridge as he fetches a bottle of water.

"Oh jeez," he laughs. "I hope my coaches don't see this! Left over KFC, that's my favourite. I get one bucket for myself - three chicken pieces and eight wings. Us island boys like our food. Growing up with all my siblings, our parents had a pretty big fridge to fill.

"It will be nice when I move to Bristol next year because my brother's wife cooks up good island meals: taro and things like that. Maybe we'll start roasting whole pigs to remind us of home."

The classy winger will move to England with his girlfriend, Lineti. The couple will marry next summer and plan to set up a new home in Bristol, 11,000 miles from New Zealand, as proud memories of Piutau's 17 All Blacks caps become ever more distant.

"I loved every second with the All Blacks,' says Piutau, who was left out of the 2015 World Cup squad after announcing his first move to Europe would come in 2016.

"I still have my jerseys back at home. They were the best feelings. I played 17 Tests and was lucky enough to win them all.

"Hearing I didn't make the World Cup was the hardest phone call I've had in my career. I was sat in the kitchen with my parents and I'd been waiting by the phone for 10 days. I just remember the words, 'Sorry, we're going with someone else'. My heart dropped. It was my dream back then, but that's the reality of sport."

That leads on to the million-dollar question: in this unique story of faith meeting fortune, will we see Piutau back in an All Blacks jersey?

"To be honest, probably not," he says, showing no tone of regret.

"If there was a time, it would have been at the end of this season, instead of going to Bristol. I'm really happy. I'm 25 and I've left that chapter behind. I've left that there. I just want to stay here now. Yeah ... that's how it is."