RNZ reports the rules state that athletes are meant to shoot in shorts but the 18 year old said he wanted to do something different to showcase his heritage and the judges agreed to the request.
"It gives you a bit of a boost to know, to actually feel the tradition and the culture. The last couple of days I was thinking of it and I tried it on and I shot fine in it with the wind but it was mainly just to show how proud we are to be Tongan, the team in general...there's a line called "Tongan Pride"...it had to show some of my culture, some of what we actually have in Tonga."
Adding to the occasion, the Olympic newcomer pushed his opponent, world number five Sjef Van Den Berg from the Netherlands, right to the end in their round of 32 match at the weekend.
"I can walk off the line saying I shot the best I could against an amazing archer. He finished the match with a ten when he needed a ten...that really shows some classy shooting. Not many archers can make that shot and with the amount of pressure on his shoulders because in all honesty I had nothing to lose. He had everything to lose and to be able to come back in it with that last arrow and just finish it off is very impressive. There's no shame in losing to an archer who is honestly just better on the day."
Tonga's flagbearer in Rio, Pita Taufatofua, also wore a tupenu during the opening ceremony and caused a stir after the cameras zoomed in on his coconut-oiled body.
Arne Jensen said it was good to be able to bring the attention to Tonga.
"A lot of us perform a little bit better with the support that we get from Tonga and the fact that we put Tonga on the map a little bit with our opening brought a lot of support from not just Tongans in Tonga but Tongans all over the world. It gives us a bit more drive, a bit more motivation - I think it was a big plus. We did this just to show that we were proud to be Tongan and we wanted people to see Tonga for what it was - not just get all dressed up in a suit, the typical sort of thing, you know?"
Jensen said his role now is as the official team cheerleader for Tonga's remaining four athletes still to compete in Rio.