There were some teething problems during the programme's pilot phase. A few teachers complained that it made classes unruly and that some of the sexual material was confronting for more conservative students.
Despite those initial hurdles, later reviews found that a majority of students had responded positively to the programme.
ACC injury prevention manager Mike McCarthy said the corporation's board had now approved additional spending of $18.4m to expand it to 180,000 students around the country.
It is one of several preventative measures ACC is backing in a bid to reduce mental and physical injuries caused by sexual violence.
The number of sensitive claims – which relate to injuries from rape, sexual assault, and child abuse – has risen by 88 per cent in the past five years because of more generous state support for victims and movements like #MeToo. Treatment costs alone passed $50m last year, up from $12m in 2013.
ACC data shows sexual violence rates are highest among people in their late teens and early 20s. The data is based on when people make a claim, and the average delay between an assault and a claim in New Zealand is 16 years.
"It really indicates that we've got some pretty significant child abuse problems in our country that we haven't looked at in that sort of holistic, cultural way in New Zealand society," McCarthy said.
"That's the biggest nugget here – that culturally we've got some stuff happening that we don't talk about or accept.
"We then see it down the track, where people start seeking help, but we're not actually addressing it right back at the prevention point."