When Massey High School student Josh Tangimetua got an envelope with a letter from the school's youth support worker, he thought he was getting another detention.
Instead, it was an invitation to work with 12 famous artists on a project that has completely changed his thinking.
"I was a pretty bad tagger," he said. "I was hanging out with friends, wagging school, not even coming to all my classes, hanging out at the parks and stuff.
"But when this came around, I started changing my attitude towards it. It taught me that artwork is not to be used for illegal stuff, but to be used for amazing things."
Josh, 14, is one of 18 students who have worked with TMD Crew artists over the past four weekends painting a big water tank behind the school as TMD's 20th anniversary project.