Saia Day, from Holonga, ran in the cross-country event on Sunday.
"I did alright. I finished," he said.
The 13-year-old said it was "very different".
"We're not used to running on hills and different terrain."
The whole Tongan contingent, and their Pāpāmoa hosts went and watched Day compete on Sunday, cheering and running alongside him – spurring him towards the finish.
Yesterday, Day was competing in the 50m breaststroke.
"I think it will be a good experience."
All four Tongan athletes and five of their family members are staying with three households on Grenada St in Pāpāmoa.
They arrived in Tauranga on Friday afternoon.
"We really appreciate the fact that these Tauranga families are willing to accommodate us. That's the first time we've met with them, but they treat us like part of the family," Suliana Afu, mother of Vaoahi, said.
"We see this as an opportunity for them [the kids] to further develop because we didn't have the proper pool in Tonga, but also we don't have a professional coach."
Instead, the parents themselves have been doing the coaching.
"We're just looking on the YouTube and stuff. And if anyone comes to Tonga and they've been swimming before, we just ask them to help," Kilisitina Uhi, mother of Koti, said.
She said the youngsters have been training hard all year and have also taken part in competitions in Fiji and Auckland.
At the Auckland event earlier this year, the team met a woman named Jane Logan, a swim coach, who offered to train and accommodate them for free ahead of the AIMS Games.
So last week was spent in Auckland. The team stayed at Logan's house and trained every morning and afternoon – mainly focusing on diving and turning. The pools they train at in Tonga don't have starting blocks.
Lua Langi, the mother of 12-year-old swimmer Keli (who was racing in 50m and 100m breaststroke and 50m freestyle), said some promises have already been made for when the athletes finish their events.
"Very simple [requests] from Tonga," she laughed. "McDonald's, movie theatre and the mall."
All things, she said, that they don't have back home.
The kids were also keen to hit the beach – but were feeling the cold a bit.
The Tongan visitors said they feel at home with their Tauranga hosts; like they've known each other for years.
Host Terry Hurdle said: "We've been looking forward to it for so long; it's just been so much fun. We've had lots of laughs, we've been all together."
The kids have been going backwards and forwards among the three houses, he said.
"So it's like a little community, which is very good.
"It's good for us; it's good for them. We're learning their culture, they're learning our culture, and it's so great to be able to interact with each other. It's been a lot of fun. We'll do it again."
Neighbour Barb Remihana agreed.
"I would just like to say how privileged we are to have the Tongans here and how much fun and enjoyment we have got from them as well. They've been so helpful and so grateful. And it's just been a real experience for us to be able to share it with them."