The quartet will be competing at this weekend's Oceania Junior Championships and Leo is already in the national elite boys' squad, with Apa and Mason part of the New Zealand development squad.
"It's different," agreed Leo. "Most Islanders play rugby but I didn't like the sport for some reason. I didn't like hard contact, smashing into people.
"I followed my Dad down, then picked up a racquet. I like squash because it's creative, fun and it's an individual sport. You don't have to rely on anyone."
Leo's squash prowess - and that of his precocious relatives - can be traced back to Peter Fatialofa.
Affectionately nicknamed Fats, the Manu Samoa captain and Auckland stalwart took up squash as a way to keep fit during summer.
He persuaded his brother Apa (Leo's father) to come along and it became a serious pursuit, with Apa becoming a fixture around the Henderson Squash Club, often with his children and grandchildren in tow.
"They used to just run around the club," recalled Apa. "Then they suddenly all jumped on the court when they were six, seven and eight and it blossomed from there. We trained them, then put them on to the experts after they got the basics. "
Leo is entranced by the sport. He trains six days a week and spends plenty of time studying matches on TV. There's a long way to go but he seems on the right track.
"He is very disciplined for a young kid," said coach Glen Wilson, who won three national titles and reached a high of world No 24.
"He's a couple of years ahead with his mentality. He loves the game, he's talented and innovative and always wants to learn."
Wilson says the apex of Leo's career so far was in the US last year, when he finished seventh in the under-15 age group from a field of 128 drawn from 37 countries.
"Having that exposure broadened his career," said Wilson. "Now he knows exactly where he wants to go. It helps that he is surrounded by squash. They are a team within themselves and all tracking at the same level. Maia only took up squash last year and then she won the New Zealand [under-11] title."
Leo has also found the perfect mentor in a burgeoning friendship with Paul Coll.
The first Kiwi male in two decades to break into the world's top 20 and currently ranked 13th, Coll was a Fatialofa house guest last year.
"That was amazing," said Leo. "I got a text from a friend of his asking if Paul wanted to stay at our house when he was in Auckland. I begged my Dad, please ... please. We watch him all the time, his dives and the way he gets everything back.
"It was quite funny - when he was here, we turned on YouTube on our TV and all of the recommended videos were him playing."
Leo also picked up plenty of tips from 24-year-old Coll.
"He trains really hard - he even trained on Christmas Day - and he was really professional with everything. He was always eating sushi for dinner while we were having meat and pasta and chips. He just said no thanks."
Leo doesn't lack role models. Aside from his famous late uncle Peter, Sevens captain DJ Forbes is a cousin, along with former All Black Kevin Senio and ex-Blues player John Senio.
"There's plenty of family heritage in sport," said Leo. "DJ is really good. He's always giving me advice, teaching me how to strive for my goals."
At the moment, those goals include making the New Zealand under-19 team for the world junior championships next year ("He's very young but an outside chance," said Wilson), a US college scholarship and a professional career.
Henderson Squash Club was teeming with activity yesterday, as host of the Oceania Junior Championships. There were coaches, parents and young players everywhere you looked, including Leo, Apa Junior, Mason and Maia.
Walk around and you can feel the history. Hanging on one wall are mementoes from the 1987 women's world championships staged here, where Susan Devoy fended off rivals such as Lisa Opie and Vicki Cardwell for her second world title.
Outside the main show court, the giant scoreboard from the 1983 world squash championships, at the time the richest event in squash history, saw local Stuart Davenport duelling with Pakistan's Jahangir Khan and Qamar Zaman.
The sport in this country has faded since those golden years, though the recent exploits of Joelle King and Coll have restored some lustre.
And who knows, in a decade or so, one or more of a certain well-known Samoan family could be making their own mark.
"You don't like to make predictions with someone so young but Leo could definitely go all the way," said Wilson. "He certainly has a lot of the early attributes to make it as a professional. The step from junior to senior is massive but Leo has the right mindset."
