Shirley Boys' High School and Rangiora High School are the only schools in Canterbury who have hosted a group that educates boys about male sexual assault.
The Male Survivors of Sexual Abuse Trust (MSSAT) approached almost every school in Canterbury but garnered little interest.
Trust manager Ken Clearwater said feedback from the schools that did take up the offer was positive. Boys appreciated having a safe space to discuss the topic.
"Shirley Boys' was interesting because I left 100 booklets with the [guidance] counsellor... a few days later they'd run out of them. Boys want to know about these things."
Clearwater said MSSAT was the only agency in the country that worked with male victims of sexual assault and abuse.
Female assault on men was recognised in law in 1998 after pressure from MSSAT. Before then, men assaulted by women were not eligible for compensation through ACC.
The ACC Act was amended, meaning boys and men assaulted by women were granted access to counselling.
"Over 50% of the men we work with have been sexually violated by female perpetrators," Clearwater said.
He said the trust had existed for 20 years and was as necessary today as it was 20 years ago.
"Wherever there are vulnerable children there is sexual and physical violation."