"It was a really low thing to do to someone and, for obvious reasons, the tourist has decided to go back home to Japan and cut short his holiday.
"He was planning to spend another six months here."
The driver of the car is described as a Maori or Pacific Island male, large build, around 175cm tall, with short hair and a goatee.
He was wearing a black T-shirt with white writing on it, and Brisbane Broncos-branded maroon shorts.
Mr Whiu said police were keen to hear from anyone who saw the two men or the car, described as a dark-coloured green or blue Mitsubishi Challenger or similar, in the Kawakawa area around 10.40am on Monday.
The had offender indicated to the tourist that he was heading north.
People can contact police on 09 404 3152 or to provide information anonymously call Crimestoppers on 0800 555 111.