Neither expected to be named in the under-17 NZ squad and said it came as "a bit of a shock".
More so for Caleb who three days earlier was named in the national under-17 beach volleyball squad tocontest January's Oceania Championships in Vanuatu.
Caleb, who stands 1.98m (6ft 4in) and weighs 104kg, plays as No 8. His school life is pretty much a constant round of training for sports when he's not in class. He leaves for school on the bus but his dad Mark, who played his rugby in Auckland and North Shore, usually has to pick him up about 8.30pm, unless he's made arrangements to stay with a friend.
Mark reckons Caleb "eats anything and everything" but his son says he has advice from a nutritionist about the diet he should be following and he tries to stick to it.
Isaac is 1.75m tall and weighs 78kg. He plays in the mid field or on the wing. Recently he's taken up sevens and loves playing the shorter version of the game. His school teams cleaned up the BOP secondary schools sevens tournament at the weekend.
His parents, Cherie and Ngawhika of Manoeka, are "very proud" of their boy, who has a twin sister.
It is pretty unusual for 15-year-olds to be promoted to play in under-17 teams. Caleb said one of his coaches told him the most recent guy who did that was Richie McCaw.
"But I dunno if he was having me on or what," he says with a smile.
If both boys stay competing, without injuries, they will be 19 when the next under-20 team is selected for the next Junior World Cup.
Watch for them among the possibilities for the 2019 Rugby World Cup when they'll be aged 23.
Meanwhile, this year's cup celebration in Te Puke saw the Arts, Rugby, Culture and Heritage (Arch) display raise enough to give about $520 to all four service clubs whose members staffed the entry and minded the exhibits - Kiwicoast and Te Puke Lions and Te Puke and Maketu Rotary clubs.
Among their duties, the service club members sold raffles tickets for two rugby balls signed by the All Blacks who visited town before the cup kicked off - Daniel Carter, Richard Kahui and Isaia Toeava - and a Bay Steamers centennial jersey.
The rugby balls were encased in perspex with a plaque attached by Te Puke Jeweller's Rod Pearce.
He presented them to the lucky young lads whose numbers were drawn - Leevi Manahi, 6, and brothers Louie, 5, and Kirwan, 10, Te Hiini.
The rugby jersey went to Joan Hood, who was delighted and says she might wear it "around home and in the garden but not to town".
The raffles raised $750, which was presented to Te Puke Community Board chairwoman Karyl Gunn, a trustee of the Community Hub which will benefit from the donation.
Organiser of the Arch exhibition, John Beech, presented the cheques to the service clubs and thanked them for their voluntary work which helped make the event a success.
He also thanked those who contributed items to the display - artists, rugby clubs, Arohanui Trust, Te Puke Floral Art group and Instant Effects Nursery and Tauranga Ethnic Council.