"Mr Simpkins remains on full and normal duties as director of rugby."
Simpkins' father, Robert Miroa Simpkins, 59, also pleaded guilty to one charge of assault on a child under 14 and one charge of assault with intent to injure in relation to the same incident.
The pair had chased three boys after one of them stole a pair of shoes from outside their house. During the incident, Ngarimu Simpkins pinned one on the ground and punched him in the head more than once.
He also kicked or punched the boy in the stomach and later punched one of the boys in the face, knocking him to the ground.
Two boys were taken to hospital where they were treated for injuries. A third boy was uninjured but shaken.
The pair will be sentenced on August 26 at the Rotorua District Court.
Ministry of Education's Steve Stuart, head of sector enablement and support said the ministry could not comment on individual cases, but supplied the Rotorua Daily Post with a general statement.
"Like all schools, our first priority is to do everything we can to keep children safe.
"A number of measures have been introduced recently to strengthen safeguards around people who work with children," he said.
The Ministry of Social Development states that any organisation funded by the government must observe the provisions of the Vulnerable Children Act.
A police vet must be obtained for anyone appointed to work during normal opening hours.
