Her son, Joshua, was convinced he hated school, that it was boring and he would rather be in a fulltime job.
"Every day I told him, 'Boy, without your education you won't get anywhere'." But nothing she said or did could keep him in school, she said.
"I think maybe because I didn't do school and I'm okay he thinks that he doesn't have to," Ms Tohu, who left school at 15 to care for her younger siblings, said.
She often wished she had stayed at school, and is now in a fulltime barista course, which she hopes is a good example to her son.
Ms Tohu said all parents and caregivers needed to be aware that it was they who would face the punishment for truancy, not the children.
"Keep hammering on at them so you don't end up in the same position I am in," she said.
She said Joshua was too young to realise the full extent of what he had put his mother through.
John Gough is the truancy officer at Whangarei Boys' High School and he is facing an uphill battle ensuring all boys are attending school. It is his job to follow up all unexplained absences with parents, and seek interventions with community services when necessary.
He said this was the first conviction of a parent for failing to ensure a child attended school that he had seen in Whangarei.
"My intention is not to get the parents fined. My intention is to get the kids back in school, and a $300 fine (the maximum for the charge) is not going to help anyone," he said.
Mr Gough said four more cases in Whangarei were destined for the courts over the next couple of months and he was not sure whether they would end in convictions.
Ms Tohu and Mr Gough expressed hope that the future would be easier for Joshua. He was going through alternative education with People Potential.
Most recent figures from the Ministry of Education say nationally 29,000 students are truant from school on any given day, which translates to an overall rate of 4 per cent.
Rates for Northland dwarf that, with the Far North, Whangarei and Kaipara scoring 7, 5.2 and 5 per cent respectively.