'Can you please come to my school and help me?'
Judge Andrew Becroft intervened in the case after the boy, 13, wrote to him following his suspension for his involvement in a fight.
The boy moved to the school last year as a directed enrolment, meaning the Ministry of Education ordered the school to enrol him after it initially refused.
Becroft recently defended the rights of such children after the Principals' Federation suggested schools refuse to enrol them unless the ministry provided sufficient support to keep them and others safe.
The boy's letter, provided to RNZ by his mother, said his school would not let him participate in regular school activities and kept him in a room with a teacher away from but in full view of other children.
"I'm having a really hard time at school at the moment and hate being treated so differently to all the other students. I just want to make some friends and be treated like everyone else. I hate being bullied and laughed at because the teachers treat me differently and so do the other students," he wrote.
"Can you please come to my school and help me? I want to go to school and just be like everyone else. This is making me feel depressed and angry. Sometimes it makes me feel like I shouldn't exist."