"The overall effect on him has been nothing short of profound," Power said.
The sexual abuse began when the victim was only 7 years old, when the defendant, nearly a decade his senior, would take him to the beach to commit the indecent acts.
Court documents showed that on one occasion another young boy was nearby when Remus committed the seafront violation.
He told the victim to prepare to put his school uniform on quickly and hide if anyone spotted them.
During that same timeframe — between October 2007 and January 2009 — Remus grabbed at the boy's genitalia while they were in a car.
An adult witnessed the act and confronted the defendant but he feigned innocence.
The summary of facts also detailed another occasion where the offending was nearly uncovered by Remus' mother, while he was semi-naked with the boy.
The violations continued after the defendant became an adult.
The court heard Remus followed the victim around in his car and told him to get in, again taking him to an isolated beach where the final sexual act took place.
"The victim said to the defendant he didn't like it and it wasn't OK; that he did not want to see the defendant again," the summary said.
When police interviewed Remus more than nine years later he admitted he and
the boy had "got up to some things they shouldn't have" but said it was "nothing ever serious".
The defendant described himself as a "confused kid" and estimated there had been 10 occasions when the crimes had taken place.
Remus told police he wished the victim had come forward sooner.
A report assessed him as presenting a medium risk of harm to others but counsel Anne Stevens QC said there was no suggestion her client was an ongoing threat to others.
She stressed his remorse and said the crimes would be "with him on a daily basis and always will be".
Remus had complex medical and psychological needs, Stevens said, but the Crown argued they could be adequately managed in prison.
Because of his term of imprisonment, he was automatically added to the child sex offender register.
Judge Phillips declined an Otago Daily Times application to photograph the defendant.