The All Blacks' latest rising star has opened up about his remarkable rise to the top of world rugby, including a late-night pizza run during his previous life as a bouncer.
The man affectionately called 'Big Karl' by fans, has become a cult figure in recent times thanks to his down-to-earth disposition and impeccably groomed moustache. He's not too shabby on the rugby pitch either.
Tu'inukuafe – a self-proclaimed homebody, Netflix watcher and family man – says he's still getting used to the spotlight that comes with being an All Black.
"I'm kinda always nervous," Tu'inukuafe told ANZ Sports Scene. "So I kind of get lost for words sometimes. It does get a bit easier but I'll never get used to it I reckon."
The 25-year-old was given his All Black opportunity when he was selected as injury replacement for Tim Perry, who was ruled out of the first two mid-year tests against France.
After a few impressive outings, Tu'inukuafe was entrusted with a start in the All Blacks' first test after a shock loss to the Springboks, an opportunity he grabbed with both hands.
The 35-17 win in Buenos Aires turned out to be a breakout performance for Tu'inukuafe, showcasing his strengths – world-class scrummaging, running ability, natural athleticism – and potential to become the best prop on the planet.
With Crusaders prop Joe Moody returning to fitness, Tu'inukuafe says he welcomes the competition for the No 1 jersey, even conceding that he thinks his fellow prop is the best.
"It's been said that he [Moody] is fit and ready to play and I'm real happy for that to be happening just cause I rate him as number one," he says.
"So it's definitely something for me to learn from and he's definitely got a lot of experience so I could take tips. I'm just happy for him to be back and would like to work for him again."
Tu'inukuafe has become one of the feel-good stories of the year, from revelations about his former life as a bouncer to his life-changing 30kg weight loss.
Always the optimist, Tu'inukuafe looks back fondly on his time as a bouncer, a profession that doesn't always lend itself to the most calm or friendly environments.
He credits his positive experience working the Auckland night-life to being part of a good team, just like he is now with the All Blacks.
"I always worked with good teams that are always helpful with all the fuss."
He says his favourite memory of working in the profession was the time a pizza chain magnate's grandson treated him to a "big feed".
"The actual grandson of the owner of Sal's [Pizza] came through and we looked after him, and he just opened up the Sal's on Queen St.
"And since we looked after him, he let us come into the Sal's to have a big feed after the night was over. It was pretty good. A good buzz."
There may not be a lot of glaring holes in his rugby game, but he admits his weakness is a love of good food, something he's had more opportunity to do on his overseas travels with the All Blacks – his favourite being Malva pudding from South Africa.
"Apparently it's like something common they do over there. It's just pretty much a pudding with caramel. Throw some ice-cream on it and it's pretty good," he says with a laugh.
"With trainers and nutritionists coming along, they keep a good eye on you. Especially if you're someone like me, they'll keep an extra eye on you just to watch out for any blowing up. But yeah you get to experience pretty much everything you wanna try it's just in moderation I guess."
He's certainly left Kiwi rugby fans hungry for more.