Four of the men were each charged with one count of unlawful sexual connection with a girl aged under 16, while one was charged with two counts. All were first-time offenders and pleaded guilty.
Judge Bidois said the situation was not similar to "Roastbusters", referring to a group of boys in Auckland who supplied girls with alcohol and took advantage of them. No charges were laid in that case, leading to a public outcry and criticism of how police handled the complaints.
In the Opotiki case, all of the incidents were either in the homes of the defendants or friends, or in one case, a car.
"There is concern about the handling of the case by the school and the police," Judge Bidois said.
"I don't know what the mechanics were of the investigation ... and the handling is not for me to comment on. The focus should be on that there was criminal offending and the guilty pleas are a recognition of that. You accept what you did was wrong."
Judge Bidois said the traditional approach was young people needed protecting from themselves. In this case, the girls, who largely rejected the label "victim", had instead become victimised by the system, he said.
"Maybe the law needs to be revisited or at least the sentencing approach to these kind of things needs to be reassessed. In a lot of ways the world has changed ... but underage sex has been around for a long time."
Judge Bidois said he knew of schoolyard relationships which lasted more than 30 years.
The judge's comments came after lawyers criticised the police handling of the case, saying the investigation had a more harmful impact than the actual offending.
Earlier in the hearing, one of the girls tearfully read a victim impact statement to the packed courtroom, where dozens of people were forced to sit on the ground.
"I know I'm under 16 and and legally cannot give consent but I did," she said.
"Police have not listened to me or how I felt."
She did not want to be classed as a victim and the most harmful part of the situation had been the police investigation.
"The police are determined to make [the accused] pay and make me feel like what I had with him was dirty and disgraceful. There was never anything disgusting about us being together."
After the hearing, police released a statement thanking the families for their involvement in what had been a "very challenging" case.
Police began investigating the five cases late last year after several of the girls spoke to a deputy principal at Opotiki College.
The girls told the teacher they knew of at least three girls who had engaged in sex with the older boys.
