Shechaniah, who has a family link to Aitutaki in the Cook Islands, used the circle of stars on the national flag as a graphic on his T-shirts, and his mates, all Ngati Kahungunu ki Wairarapa boys, had also designed clothing that revealed their identities.
The boys had modelled and worn their outfits before sending the garments in for judging in the competition.
They had won their way through to the finals, which offered winners more than $30,000 in prizes - but failed to place.
They remain keen to re-enter their designs in upcoming competitions.
The boys said Ms Goodwin and "the belief she had in us" had fuelled their drive to create the clothing, and each believed a career in fashion design was worth considering.